<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019b285d-6025-79f0-b759-b3b31f82fc6a,g:ef2ffa17-f83c-4380-93b5-c6be6a9be28f-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.wearelegence.com/role/Cover" xlink:type="simple" xlink:href="lgn-20251231.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019b45c0-2ac1-70fe-9ef0-7987fa3bd299" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentInformationTable_019b45c0-2ac1-70fe-9ef0-7987fa3bd299" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019b45c0-2ac1-7a77-8e06-020ebe83c376" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019b45c0-2ac1-70fe-9ef0-7987fa3bd299" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019b45c0-2ac1-7a77-8e06-020ebe83c376" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-7a77-8e06-020ebe83c376_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b45c0-2ac1-7a77-8e06-020ebe83c376" xlink:to="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-7a77-8e06-020ebe83c376_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-764d-85c8-a37f72628758" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b45c0-2ac1-7a77-8e06-020ebe83c376" xlink:to="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-764d-85c8-a37f72628758" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019b45c0-2ac1-7570-890b-f1b9c818cfba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-764d-85c8-a37f72628758" xlink:to="loc_us-gaap_CommonClassAMember_019b45c0-2ac1-7570-890b-f1b9c818cfba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019b45c0-2ac1-7aa6-b017-b3328878fa9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b45c0-2ac1-764d-85c8-a37f72628758" xlink:to="loc_us-gaap_CommonClassBMember_019b45c0-2ac1-7aa6-b017-b3328878fa9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019b45be-b93a-7195-83f0-bfbc47f5d1f6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentType_019b45be-b93a-7195-83f0-bfbc47f5d1f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport_019b45bf-1c25-7f42-8356-ed665a7e41fe" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentAnnualReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentAnnualReport_019b45bf-1c25-7f42-8356-ed665a7e41fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019b45be-b93a-7d11-8840-2f0690eea29f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentPeriodEndDate_019b45be-b93a-7d11-8840-2f0690eea29f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019b45be-b93a-7730-965d-3213e6dfea35" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_CurrentFiscalYearEndDate_019b45be-b93a-7730-965d-3213e6dfea35" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019b45bf-3547-7d4c-a1db-06bc02baf395" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentTransitionReport_019b45bf-3547-7d4c-a1db-06bc02baf395" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019b45be-b93a-7097-a40c-98f4c7b20ca2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityFileNumber_019b45be-b93a-7097-a40c-98f4c7b20ca2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019b45ca-18dc-7126-bbc7-4956278c2929" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityRegistrantName_019b45ca-18dc-7126-bbc7-4956278c2929" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019b45bf-9f1a-7226-9df3-bbb4dd742f4c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019b45bf-9f1a-7226-9df3-bbb4dd742f4c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019b45bf-9f1a-791a-bf94-1c23e47ee1e0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityTaxIdentificationNumber_019b45bf-9f1a-791a-bf94-1c23e47ee1e0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019d2548-cd92-797a-b290-88e9a5a483df" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityAddressAddressLine1_019d2548-cd92-797a-b290-88e9a5a483df" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019d2549-2443-7f8d-a1f1-76e0eed24ee0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityAddressCityOrTown_019d2549-2443-7f8d-a1f1-76e0eed24ee0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019d2549-50fd-7050-9e61-11357512757b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityAddressStateOrProvince_019d2549-50fd-7050-9e61-11357512757b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019b45bf-9f1a-7a5f-b611-ac918b0b7223" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityAddressPostalZipCode_019b45bf-9f1a-7a5f-b611-ac918b0b7223" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019b45bf-dbd3-7b91-bebc-54fe10212d6f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_CityAreaCode_019b45bf-dbd3-7b91-bebc-54fe10212d6f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019b45bf-dbd3-7070-8a74-e74e388071ff" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_LocalPhoneNumber_019b45bf-dbd3-7070-8a74-e74e388071ff" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019b45c0-2ac1-73e6-8b86-02e7e46aad06" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_Security12bTitle_019b45c0-2ac1-73e6-8b86-02e7e46aad06" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019b45c0-2ac1-7f0c-a1aa-3be5d057c7e0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_TradingSymbol_019b45c0-2ac1-7f0c-a1aa-3be5d057c7e0" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019b45c0-2ac1-7d35-8444-3a124b25af29" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_SecurityExchangeName_019b45c0-2ac1-7d35-8444-3a124b25af29" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_019b45c1-5044-748b-b9b5-3d0f5eca1850" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityWellKnownSeasonedIssuer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_019b45c1-5044-748b-b9b5-3d0f5eca1850" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers_019b45c1-5044-7e20-bb9b-d84720f06aa8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityVoluntaryFilers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityVoluntaryFilers_019b45c1-5044-7e20-bb9b-d84720f06aa8" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019b45c1-8e12-7a4b-8b9f-62a401bcc2fd" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityCurrentReportingStatus_019b45c1-8e12-7a4b-8b9f-62a401bcc2fd" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019b45c1-8e12-7dca-85b6-72edc8cb1772" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityInteractiveDataCurrent_019b45c1-8e12-7dca-85b6-72edc8cb1772" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019b45c1-c797-798a-9490-af74e18ed3c1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityFilerCategory_019b45c1-c797-798a-9490-af74e18ed3c1" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019b45c1-c797-7f89-80b4-d7f57d3fa611" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntitySmallBusiness_019b45c1-c797-7f89-80b4-d7f57d3fa611" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019b45c1-c797-7c19-b277-c93a3edcdaa1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityEmergingGrowthCompany_019b45c1-c797-7c19-b277-c93a3edcdaa1" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag_019b45c1-f606-71c7-87d6-9f7c66dfc1b5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_IcfrAuditorAttestationFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_IcfrAuditorAttestationFlag_019b45c1-f606-71c7-87d6-9f7c66dfc1b5" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFinStmtErrorCorrectionFlag_019b45c1-f606-7c4e-90b3-a824b64702fa" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFinStmtErrorCorrectionFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentFinStmtErrorCorrectionFlag_019b45c1-f606-7c4e-90b3-a824b64702fa" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019b45c1-f606-7bf3-b04e-20181dadd479" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityShellCompany_019b45c1-f606-7bf3-b04e-20181dadd479" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat_019bc2e1-f911-70aa-96ae-95ead4f670e1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityPublicFloat_019bc2e1-f911-70aa-96ae-95ead4f670e1" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019b9b79-7e1f-7fcc-ae11-dfab386e9445" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019b9b79-7e1f-7fcc-ae11-dfab386e9445" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019b45c8-4503-79f4-abca-e5a414924e8f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_EntityCentralIndexKey_019b45c8-4503-79f4-abca-e5a414924e8f" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019b45c8-4503-78b7-a0c8-a8a381c514b9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_AmendmentFlag_019b45c8-4503-78b7-a0c8-a8a381c514b9" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019b45c8-4503-7dee-afae-ad823ab782c3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019b45c8-4503-7dee-afae-ad823ab782c3" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019b45c8-4503-7db6-89ff-2b60a5e046b9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019b45c0-2ac1-7e92-874d-88d6b59103be" xlink:to="loc_dei_DocumentFiscalYearFocus_019b45c8-4503-7db6-89ff-2b60a5e046b9" xlink:type="arc" order="33"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="lgn-20251231.xsd#ConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019b6dde-b047-79fc-9559-3c6bca048a91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019b6dde-b047-7b13-9cb0-4aea00afe5ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-79fc-9559-3c6bca048a91" xlink:to="loc_us-gaap_StatementTable_019b6dde-b047-7b13-9cb0-4aea00afe5ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019b6dde-b047-75f2-a93e-8b9cd48ac4c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019b6dde-b047-7b13-9cb0-4aea00afe5ab" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019b6dde-b047-75f2-a93e-8b9cd48ac4c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-75f2-a93e-8b9cd48ac4c3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6dde-b047-75f2-a93e-8b9cd48ac4c3" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-75f2-a93e-8b9cd48ac4c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-7c75-aa74-ec9e050f2cb6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6dde-b047-75f2-a93e-8b9cd48ac4c3" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-7c75-aa74-ec9e050f2cb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019b6dde-b047-7357-8891-0fae3e821373" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-7c75-aa74-ec9e050f2cb6" xlink:to="loc_us-gaap_CommonClassAMember_019b6dde-b047-7357-8891-0fae3e821373" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019b6dde-b047-7be2-ba9f-d8843fbbf332" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6dde-b047-7c75-aa74-ec9e050f2cb6" xlink:to="loc_us-gaap_CommonClassBMember_019b6dde-b047-7be2-ba9f-d8843fbbf332" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-79fc-9559-3c6bca048a91" xlink:to="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019b6dde-b047-7142-bbaa-453088fb238e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019b6dde-b047-7142-bbaa-453088fb238e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesNetCurrent_019b6dde-b047-7632-ad85-a45ee5a0b09d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivablesNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:to="loc_us-gaap_ReceivablesNetCurrent_019b6dde-b047-7632-ad85-a45ee5a0b09d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019b6dde-b047-779e-91c7-fd110553a2f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:to="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019b6dde-b047-779e-91c7-fd110553a2f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019b6dde-b047-7188-b344-7682025da731" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019b6dde-b047-7188-b344-7682025da731" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019b6dde-b047-741b-bb63-f924d3e33ff3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019b6dde-b047-7667-bfe2-f5ffb2684f84" xlink:to="loc_us-gaap_AssetsCurrent_019b6dde-b047-741b-bb63-f924d3e33ff3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019b6dde-b047-72c5-ae3d-88dd6e4996e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019b6dde-b047-72c5-ae3d-88dd6e4996e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019b6dde-b047-7780-b9b0-317ea3ce0fa3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019b6dde-b047-7780-b9b0-317ea3ce0fa3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019b6dde-b047-7efb-a9f4-0cd169fe08ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_Goodwill_019b6dde-b047-7efb-a9f4-0cd169fe08ca" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019b6dde-b047-7ac9-a15c-ada09955030f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019b6dde-b047-7ac9-a15c-ada09955030f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019b6dde-b047-720d-b549-d698e0a191df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019b6dde-b047-720d-b549-d698e0a191df" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019b6dde-b047-7a08-9c0e-3e949d701a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019b6dde-b047-78e3-b608-f75c867a7d6c" xlink:to="loc_us-gaap_Assets_019b6dde-b047-7a08-9c0e-3e949d701a4e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-79fc-9559-3c6bca048a91" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019b6dde-b047-7def-a834-0f2d2c4283c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_AccountsPayableCurrent_019b6dde-b047-7def-a834-0f2d2c4283c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019b6dde-b047-7b3b-bc64-f1d408e97ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019b6dde-b047-7b3b-bc64-f1d408e97ac7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019b6dde-b047-7494-bf0b-7edb178d9c2f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019b6dde-b047-7494-bf0b-7edb178d9c2f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019b6dde-b047-7950-9705-bbdc2d9f9042" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019b6dde-b047-7950-9705-bbdc2d9f9042" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019b6dde-b047-717f-8e09-63c546f507d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019b6dde-b047-717f-8e09-63c546f507d9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019b6dde-b047-7f4b-a92f-4cb875846292" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019b6dde-b047-7f4b-a92f-4cb875846292" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019b6dde-b047-7305-ad6e-b43bbac86800" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019b6dde-b047-7e99-9e85-6a4391905ecf" xlink:to="loc_us-gaap_LiabilitiesCurrent_019b6dde-b047-7305-ad6e-b43bbac86800" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019b6dde-b047-7a02-80c4-74af80a8cf75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019b6dde-b047-7a02-80c4-74af80a8cf75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019b6dde-b047-7058-8971-9f14f683359d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019b6dde-b047-7058-8971-9f14f683359d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementLiabilityNoncurrent_019b6dde-b047-72b2-b86e-02ff21e070a1" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_lgn_TaxReceivableAgreementLiabilityNoncurrent_019b6dde-b047-72b2-b86e-02ff21e070a1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019b6dde-b047-75cc-bdce-adf032b82542" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019b6dde-b047-75cc-bdce-adf032b82542" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019b6dde-b047-740a-b84a-41d0469e6134" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019b6dde-b047-740a-b84a-41d0469e6134" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019b6dde-b047-757f-bf2f-71141f21bfee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_Liabilities_019b6dde-b047-757f-bf2f-71141f21bfee" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019b6dde-b047-7308-836b-cbc5d2da7418" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019b6dde-b047-7308-836b-cbc5d2da7418" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersCapital_019b6dde-b047-7a54-81bf-a333ccbf479f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_MembersCapital_019b6dde-b047-7a54-81bf-a333ccbf479f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019b6dde-b047-71dd-9275-fa9c0bdf64b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_PreferredStockValue_019b6dde-b047-71dd-9275-fa9c0bdf64b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019b6dde-b047-7e62-b2c7-f94566dc710a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_CommonStockValue_019b6dde-b047-7e62-b2c7-f94566dc710a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019b6dde-b047-751b-8fe6-898e87dd854c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019b6dde-b047-751b-8fe6-898e87dd854c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019b6dde-b047-77e9-9c12-54f122546094" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019b6dde-b047-77e9-9c12-54f122546094" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019b6dde-b047-7ae0-8828-de7deee4659f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019b6dde-b047-7a5f-81e5-09515e0da94b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019b6dde-b047-7ae0-8828-de7deee4659f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019b6dde-b047-7fa7-946b-5c2cd94b22ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_StockholdersEquity_019b6dde-b047-7fa7-946b-5c2cd94b22ed" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019b6dde-b047-73fa-890a-31ee69a9e144" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_MinorityInterest_019b6dde-b047-73fa-890a-31ee69a9e144" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6dde-b047-7ac2-a5af-9abd8f3c1815" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6dde-b047-7ac2-a5af-9abd8f3c1815" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquity_019b6dde-b047-785b-8a5d-f68b1bae1c8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_MembersEquity_019b6dde-b047-785b-8a5d-f68b1bae1c8f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_019b6dde-b047-702c-9eba-5c0460de153f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_019b6dde-b047-702c-9eba-5c0460de153f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6dde-b047-77ee-9fc0-35045ae5f110" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6dde-b047-77ee-9fc0-35045ae5f110" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019b6dde-b047-7ac6-835e-4f90ea69e4e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019b6dde-b047-7a3b-b777-711541d5e94c" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019b6dde-b047-7ac6-835e-4f90ea69e4e2" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="lgn-20251231.xsd#ConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019b6dde-b047-7560-b536-d8f59c3a09eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_StatementTable_019b6dde-b047-7560-b536-d8f59c3a09eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019b6dde-b047-7560-b536-d8f59c3a09eb" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7ad6-d93d-7dd2-8a34-1e164a6e3f79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ad6-d93c-75fe-bf4b-69b4a3a5a24f" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7ad6-d93d-7dd2-8a34-1e164a6e3f79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019c7ad6-d93d-7d1a-8217-9564ab052e36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019c7ad6-d93d-7dd2-8a34-1e164a6e3f79" xlink:to="loc_us-gaap_RelatedPartyMember_019c7ad6-d93d-7d1a-8217-9564ab052e36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019c99a8-406a-7b22-937c-03e67ecb01ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019b6dde-b047-7560-b536-d8f59c3a09eb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019c99a8-406a-7b22-937c-03e67ecb01ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c99a8-406a-7b22-937c-03e67ecb01ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c99a8-406a-7b22-937c-03e67ecb01ab" xlink:to="loc_us-gaap_ClassOfStockDomain_019c99a8-406a-7b22-937c-03e67ecb01ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c99a8-6d5b-7d8e-94fb-cfd94b1af427" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c99a8-406a-7b22-937c-03e67ecb01ab" xlink:to="loc_us-gaap_ClassOfStockDomain_019c99a8-6d5b-7d8e-94fb-cfd94b1af427" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019c99a8-9a47-70f7-bcdf-fe8f2673100c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019c99a8-6d5b-7d8e-94fb-cfd94b1af427" xlink:to="loc_us-gaap_CommonClassAMember_019c99a8-9a47-70f7-bcdf-fe8f2673100c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019c99a8-c87b-7d93-a21e-faed9510c320" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019c99a8-6d5b-7d8e-94fb-cfd94b1af427" xlink:to="loc_us-gaap_CommonClassBMember_019c99a8-c87b-7d93-a21e-faed9510c320" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019b6dde-b047-7929-9b99-57d53710eb60" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019b6dde-b047-7560-b536-d8f59c3a09eb" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019b6dde-b047-7929-9b99-57d53710eb60" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019b6dde-b047-7929-9b99-57d53710eb60_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019b6dde-b047-7929-9b99-57d53710eb60" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019b6dde-b047-7929-9b99-57d53710eb60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019b6dde-b047-7f1b-a377-3eccb7a9b9e1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019b6dde-b047-7929-9b99-57d53710eb60" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019b6dde-b047-7f1b-a377-3eccb7a9b9e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019b6dde-b047-789e-ae14-72918b3966c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019b6dde-b047-7f1b-a377-3eccb7a9b9e1" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019b6dde-b047-789e-ae14-72918b3966c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019c7ad6-d93d-777e-bbea-d3ba6cd61e3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019c7ad6-d93d-777e-bbea-d3ba6cd61e3d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019c7ad7-b912-7b8c-8a49-7cdf5969bd44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019c7ad7-b912-7b8c-8a49-7cdf5969bd44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019c46af-1744-7822-8310-deb7c3ba3df7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019c46af-1744-7822-8310-deb7c3ba3df7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019c7adb-15ab-79b0-a47f-395c38af2b6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019c7adb-15ab-79b0-a47f-395c38af2b6e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019c7adc-4ac3-7deb-b2db-e0582e1cde36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019c7adc-4ac3-7deb-b2db-e0582e1cde36" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019d2516-4704-7b4a-bfaf-7d5f212b1c74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019d2516-4704-7b4a-bfaf-7d5f212b1c74" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019d2554-3967-7750-b053-a2d36163e2ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019d2554-3967-7750-b053-a2d36163e2ef" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_019d2554-59db-7feb-9e09-bd62fbc6a858" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_019d2554-59db-7feb-9e09-bd62fbc6a858" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019d251c-74fd-7671-ab9f-341d72da342c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019d251c-74fd-7671-ab9f-341d72da342c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019c99a2-da26-7f70-8cf5-2424fe5df2ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019c99a2-da26-7f70-8cf5-2424fe5df2ed" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019c99a3-1027-7e5f-a343-e5e6d3a07af3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_CommonStockSharesIssued_019c99a3-1027-7e5f-a343-e5e6d3a07af3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019c99a3-4bd3-73e6-b427-b4dcc52d4142" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019c99a3-4bd3-73e6-b427-b4dcc52d4142" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019c7ae0-3a9a-7d02-90b2-ea569f20af04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_Assets_019c7ae0-3a9a-7d02-90b2-ea569f20af04" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019c7ae0-74db-7909-860e-efc9af73ff71" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b6dde-b047-717a-838c-e5c1393bfbc3" xlink:to="loc_us-gaap_Liabilities_019c7ae0-74db-7909-860e-efc9af73ff71" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/ConsolidatedStatementsofOperationsParenthetical" xlink:type="simple" xlink:href="lgn-20251231.xsd#ConsolidatedStatementsofOperationsParenthetical"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/ConsolidatedStatementsofOperationsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019c7ae6-1d8c-7b88-9989-6f430d0a2cf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019c7ae5-ff86-75ac-bd6b-1ed8f039f802" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019c7ae6-1d8c-7b88-9989-6f430d0a2cf6" xlink:to="loc_us-gaap_StatementTable_019c7ae5-ff86-75ac-bd6b-1ed8f039f802" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ae6-1d8c-7070-8686-50e95db8d232" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019c7ae5-ff86-75ac-bd6b-1ed8f039f802" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ae6-1d8c-7070-8686-50e95db8d232" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7ae6-1d8c-7070-8686-50e95db8d232_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ae6-1d8c-7070-8686-50e95db8d232" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7ae6-1d8c-7070-8686-50e95db8d232_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7ae6-1d8c-71de-8a4c-e537f38fb7ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7ae6-1d8c-7070-8686-50e95db8d232" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7ae6-1d8c-71de-8a4c-e537f38fb7ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019c7ae6-1d8c-77f2-9eda-42b0ee802681" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019c7ae6-1d8c-71de-8a4c-e537f38fb7ed" xlink:to="loc_us-gaap_RelatedPartyMember_019c7ae6-1d8c-77f2-9eda-42b0ee802681" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7aee-9bbd-76a6-8151-83a329267c04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7ae6-1d8c-7b88-9989-6f430d0a2cf6" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7aee-9bbd-76a6-8151-83a329267c04" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019c7ae6-1d8c-7f05-a497-0b5a15e63b40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7ae6-1d8c-7b88-9989-6f430d0a2cf6" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019c7ae6-1d8c-7f05-a497-0b5a15e63b40" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/CondensedConsolidatedStatementsofChangesinEquity" xlink:type="simple" xlink:href="lgn-20251231.xsd#CondensedConsolidatedStatementsofChangesinEquity"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/CondensedConsolidatedStatementsofChangesinEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019c7b02-f674-73d0-a387-06c97935a41f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019c7b02-f674-7857-b884-994e2d0a0951" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019c7b02-f674-73d0-a387-06c97935a41f" xlink:to="loc_us-gaap_StatementTable_019c7b02-f674-7857-b884-994e2d0a0951" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019c7b02-f674-7958-9bf0-c780429a80c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019c7b02-f674-7857-b884-994e2d0a0951" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019c7b02-f674-7958-9bf0-c780429a80c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7958-9bf0-c780429a80c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c7b02-f674-7958-9bf0-c780429a80c7" xlink:to="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7958-9bf0-c780429a80c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7fce-bc29-32d46c7d8423" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c7b02-f674-7958-9bf0-c780429a80c7" xlink:to="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7fce-bc29-32d46c7d8423" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7fce-bc29-32d46c7d8423" xlink:to="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MemberUnitsMember_019c7b02-f674-7a72-aded-a955791bc3ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MemberUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:to="loc_us-gaap_MemberUnitsMember_019c7b02-f674-7a72-aded-a955791bc3ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019c7b02-f674-7e82-b325-f87fac988461" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:to="loc_us-gaap_CommonStockMember_019c7b02-f674-7e82-b325-f87fac988461" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019c7b02-f674-7a69-9e82-2fd7b68f5a87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019c7b02-f674-7a69-9e82-2fd7b68f5a87" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019c7b02-f674-7175-8eed-1d99d2739900" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:to="loc_us-gaap_RetainedEarningsMember_019c7b02-f674-7175-8eed-1d99d2739900" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019c7b02-f674-7dca-8386-537b40c61c09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_019c7b02-f674-7101-befe-9ac1a26f1399" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019c7b02-f674-7dca-8386-537b40c61c09" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019c7b02-f674-7c65-9301-599cec67cb94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c7b02-f674-7fce-bc29-32d46c7d8423" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019c7b02-f674-7c65-9301-599cec67cb94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019c7b02-f674-7866-b0ff-703727e23746" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019c7b02-f674-7857-b884-994e2d0a0951" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019c7b02-f674-7866-b0ff-703727e23746" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7866-b0ff-703727e23746_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c7b02-f674-7866-b0ff-703727e23746" xlink:to="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7866-b0ff-703727e23746_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7eed-be65-40377dcc5e48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c7b02-f674-7866-b0ff-703727e23746" xlink:to="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7eed-be65-40377dcc5e48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019c7b02-f674-748c-8044-5f5b5cecb70f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7eed-be65-40377dcc5e48" xlink:to="loc_us-gaap_CommonClassAMember_019c7b02-f674-748c-8044-5f5b5cecb70f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019c7b02-f674-7acf-949b-5d987df8fedc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019c7b02-f674-7eed-be65-40377dcc5e48" xlink:to="loc_us-gaap_CommonClassBMember_019c7b02-f674-7acf-949b-5d987df8fedc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7b02-f674-73d0-a387-06c97935a41f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019c7b02-f674-7693-a4ad-7e35519a6ecd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019c7b02-f674-7693-a4ad-7e35519a6ecd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019c7b02-f674-7fd6-a402-1637a5feca95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019c7b02-f674-7fd6-a402-1637a5feca95" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToMembersEquityParentIssuanceOfParentInterestsForAcquisitions_019c7b6a-200f-7e00-90cf-364d2df9a40a" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToMembersEquityParentIssuanceOfParentInterestsForAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToMembersEquityParentIssuanceOfParentInterestsForAcquisitions_019c7b6a-200f-7e00-90cf-364d2df9a40a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToMembersEquityIssuanceOfParentInterestsForContingentConsiderationRelatedParties_019c7b6f-8c06-7246-af0a-3bcdee695a1e" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToMembersEquityIssuanceOfParentInterestsForContingentConsiderationRelatedParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToMembersEquityIssuanceOfParentInterestsForContingentConsiderationRelatedParties_019c7b6f-8c06-7246-af0a-3bcdee695a1e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToMembersEquityContributionsFromParent_019c7b02-f674-747f-9a88-27252343153f" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToMembersEquityContributionsFromParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToMembersEquityContributionsFromParent_019c7b02-f674-747f-9a88-27252343153f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToMembersEquityDistributionsToParent_019c7b02-f674-74f2-9e76-3d38844c617e" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToMembersEquityDistributionsToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToMembersEquityDistributionsToParent_019c7b02-f674-74f2-9e76-3d38844c617e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToMembersEquityReclassificationOfVestedParentInterestsFromLiabilities_019c7b02-f674-76a6-a873-575ce95bb7c7" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToMembersEquityReclassificationOfVestedParentInterestsFromLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToMembersEquityReclassificationOfVestedParentInterestsFromLiabilities_019c7b02-f674-76a6-a873-575ce95bb7c7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_StockIssuedDuringPeriodValueEffectOfReorganization_019c7b02-f674-7855-b234-ce4df48b4a1a" xlink:href="lgn-20251231.xsd#lgn_StockIssuedDuringPeriodValueEffectOfReorganization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_StockIssuedDuringPeriodValueEffectOfReorganization_019c7b02-f674-7855-b234-ce4df48b4a1a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_StockIssuedDuringPeriodSharesEffectOfReorganization_019c7b02-f674-7b8c-8035-a698807fff7d" xlink:href="lgn-20251231.xsd#lgn_StockIssuedDuringPeriodSharesEffectOfReorganization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_StockIssuedDuringPeriodSharesEffectOfReorganization_019c7b02-f674-7b8c-8035-a698807fff7d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementNetLiability_019c7b02-f674-7c79-befe-ac60836d1fee" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementNetLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_TaxReceivableAgreementNetLiability_019c7b02-f674-7c79-befe-ac60836d1fee" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToAdditionalPaidInCapitalReclassificationOfSeriesAInterestsAndRestrictedSeriesCInterestsFromLiabilityToEquity_019c7b02-f674-79bb-9c1d-2174607a8d75" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToAdditionalPaidInCapitalReclassificationOfSeriesAInterestsAndRestrictedSeriesCInterestsFromLiabilityToEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToAdditionalPaidInCapitalReclassificationOfSeriesAInterestsAndRestrictedSeriesCInterestsFromLiabilityToEquity_019c7b02-f674-79bb-9c1d-2174607a8d75" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019c7b02-f674-7601-a3cd-947015c17cd6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019c7b02-f674-7601-a3cd-947015c17cd6" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019c7b02-f674-7521-8a2e-e6d00f569a69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019c7b02-f674-7521-8a2e-e6d00f569a69" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NoncontrollingInterestAllocationOfEquity_019c7b02-f674-7d8b-b36b-3f91f5617cad" xlink:href="lgn-20251231.xsd#lgn_NoncontrollingInterestAllocationOfEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_NoncontrollingInterestAllocationOfEquity_019c7b02-f674-7d8b-b36b-3f91f5617cad" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019c7b02-f674-769f-9a53-f24cedc82622" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019c7b02-f674-769f-9a53-f24cedc82622" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_019c7b6c-467f-7aa8-ba0a-9ba9a07d818d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_019c7b6c-467f-7aa8-ba0a-9ba9a07d818d" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_019c7b02-f674-7666-9586-8c8c17f17080" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_019c7b02-f674-7666-9586-8c8c17f17080" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_019c7ba3-2dbb-72db-ab3d-ae1047d00bb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_019c7ba3-2dbb-72db-ab3d-ae1047d00bb2" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019c7b9f-bf20-7c17-bb5d-709f033236d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019c7b9f-bf20-7c17-bb5d-709f033236d8" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_019c7b61-ce7e-7c80-9bfc-f412a10b7c24" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_019c7b61-ce7e-7c80-9bfc-f412a10b7c24" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentI_019c7b02-f674-7013-a73c-a469da3951f6" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentI"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentI_019c7b02-f674-7013-a73c-a469da3951f6" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentII_019c7b02-f674-7332-a24c-688ff9c2f01d" xlink:href="lgn-20251231.xsd#lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentII"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_lgn_AdjustmentsToAdditionalPaidInCapitalContributionsFromParentII_019c7b02-f674-7332-a24c-688ff9c2f01d" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c7b02-f674-79c0-a2bf-4b398bd69969" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c7b02-f674-79c0-a2bf-4b398bd69969" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c7b02-f674-7a6a-bdf7-99593f12eb1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_ProfitLoss_019c7b02-f674-7a6a-bdf7-99593f12eb1d" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c7b02-f674-7d50-b095-5cdf76292c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c7b02-f674-7dd8-8214-8eaf5159927d" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c7b02-f674-7d50-b095-5cdf76292c6e" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019c7b02-f674-757e-97d4-610be2182c32" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019c7b02-f674-71dc-b3e9-1f8eced4744c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="lgn-20251231.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019c7bab-41cb-7362-8733-8dfd5609c546" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_StatementTable_019c7bab-41cb-7362-8733-8dfd5609c546" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7bab-7bac-793c-94b0-fe2ebc734d00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019c7bab-41cb-7362-8733-8dfd5609c546" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7bab-7bac-793c-94b0-fe2ebc734d00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7bab-7bac-793c-94b0-fe2ebc734d00_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7bab-7bac-793c-94b0-fe2ebc734d00" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7bab-7bac-793c-94b0-fe2ebc734d00_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019c7bab-c16e-77e2-b0a4-f1ef2f8f6146" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019c7bab-7bac-793c-94b0-fe2ebc734d00" xlink:to="loc_us-gaap_RelatedPartyDomain_019c7bab-c16e-77e2-b0a4-f1ef2f8f6146" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019c7bab-f220-71cc-af98-7b8b6e1f6342" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019c7bab-c16e-77e2-b0a4-f1ef2f8f6146" xlink:to="loc_us-gaap_RelatedPartyMember_019c7bab-f220-71cc-af98-7b8b6e1f6342" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-7717-9912-3bf71dc89130" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-7717-9912-3bf71dc89130" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019b72d4-a3ea-7634-9711-37a9ba5f959e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-7717-9912-3bf71dc89130" xlink:to="loc_us-gaap_ProfitLoss_019b72d4-a3ea-7634-9711-37a9ba5f959e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-7717-9912-3bf71dc89130" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019b72d4-a3ea-79ba-9fcd-6f16374a3d5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019b72d4-a3ea-79ba-9fcd-6f16374a3d5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationNonproduction_019b72d4-a3ea-7bb3-a00d-bc9bc2ead920" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationNonproduction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_DepreciationNonproduction_019b72d4-a3ea-7bb3-a00d-bc9bc2ead920" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019c7ba8-2578-7bce-8063-73cddec96137" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019c7ba8-2578-7bce-8063-73cddec96137" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d1d17-2567-776e-a144-091776d9ea8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d1d17-2567-776e-a144-091776d9ea8d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019b72d4-a3ea-772d-85b5-0b7cd3be9daa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019b72d4-a3ea-772d-85b5-0b7cd3be9daa" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019b72d4-a3ea-7e28-af6a-81052b2f60aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019b72d4-a3ea-7e28-af6a-81052b2f60aa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019b72d4-a3ea-7f39-9cd6-21ac98e98f73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_ShareBasedCompensation_019b72d4-a3ea-7f39-9cd6-21ac98e98f73" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7bb4-54d9-71ae-b973-783c084e4617" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7bb4-54d9-71ae-b973-783c084e4617" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019b72d4-a3ea-7764-86b2-36d67923be47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019b72d4-a3ea-7764-86b2-36d67923be47" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementLiabilityRemeasurement_019d058a-9b33-7b9e-ad47-10d4327cc44a" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementLiabilityRemeasurement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_lgn_TaxReceivableAgreementLiabilityRemeasurement_019d058a-9b33-7b9e-ad47-10d4327cc44a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019b72d4-a3ea-73cb-9e68-38fe2ebae9dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019b72d4-a3ea-73cb-9e68-38fe2ebae9dd" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ReturnOnInvestmentInJointVenture_019b72d4-a3ea-77f4-aa10-2c9f786c9adc" xlink:href="lgn-20251231.xsd#lgn_ReturnOnInvestmentInJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_lgn_ReturnOnInvestmentInJointVenture_019b72d4-a3ea-77f4-aa10-2c9f786c9adc" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019b72d4-a3ea-7097-9a79-95cf69d0d953" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019b72d4-a3ea-7097-9a79-95cf69d0d953" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_019b72d4-a3ea-7a5e-9b23-3eb9bc9023dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_019b72d4-a3ea-7a5e-9b23-3eb9bc9023dd" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-73df-95f9-fb19dfcd0468" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019b72d4-a3ea-7626-ac94-356cc0e37b9f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019b72d4-a3ea-7626-ac94-356cc0e37b9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_019b72d4-a3ea-7a3b-87d4-22f765549e94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_019b72d4-a3ea-7a3b-87d4-22f765549e94" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019b72d4-a3ea-7f8a-91ed-8ff32a621654" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019b72d4-a3ea-7f8a-91ed-8ff32a621654" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_019b72d4-a3ea-7a6e-97fc-1333de1bb43d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayableTrade"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_019b72d4-a3ea-7a6e-97fc-1333de1bb43d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019b72d4-a3ea-7648-8517-a098358a2713" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019b72d4-a3ea-7648-8517-a098358a2713" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019b72d4-a3ea-7102-8a4d-497a5952c618" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019b72d4-a3ea-7102-8a4d-497a5952c618" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019b72d4-a3ea-7f2c-8b37-591b58e9abf8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019b72d4-a3ea-7f2c-8b37-591b58e9abf8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019b72d4-a3ea-7067-b17e-ccc2ea4b9787" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019b72d4-a3ea-7067-b17e-ccc2ea4b9787" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019b72d4-a3ea-71db-be4e-5fcd8f5d4c48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019b72d4-a3ea-7d46-b842-22d0bd821715" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019b72d4-a3ea-71db-be4e-5fcd8f5d4c48" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019b72d4-a3ea-7444-bffc-bec1639824d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019b72d4-a3ea-7717-9912-3bf71dc89130" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019b72d4-a3ea-7444-bffc-bec1639824d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019b72d4-a3ea-7def-a06c-45c6f698298e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019b72d4-a3ea-7def-a06c-45c6f698298e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019b72d4-a3ea-70b4-9ebf-8b9f6af1ae19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019b72d4-a3ea-70b4-9ebf-8b9f6af1ae19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_019b72d4-a3ea-78e8-aff1-fa9286c5055d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_019b72d4-a3ea-78e8-aff1-fa9286c5055d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_019c7bbd-eca1-7583-aa8f-10de6c289e4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:to="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_019c7bbd-eca1-7583-aa8f-10de6c289e4c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019b72d4-a3ea-7e59-82ff-a0c4ce5bbd23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019b72d4-a3ea-73bb-a8e7-79c071a1027a" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019b72d4-a3ea-7e59-82ff-a0c4ce5bbd23" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_019b72d4-a3ea-7371-bc5f-6903f1ca1f6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_019b72d4-a3ea-7371-bc5f-6903f1ca1f6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_019b72d4-a3ea-76b8-a5e4-38fd68c04573" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_019b72d4-a3ea-76b8-a5e4-38fd68c04573" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfNotesPayable_019b72d4-a3ea-7b86-b38b-65746c8b4b87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_RepaymentsOfNotesPayable_019b72d4-a3ea-7b86-b38b-65746c8b4b87" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_019b72d4-a3ea-786d-bd20-56027e23d544" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_FinanceLeasePrincipalPayments_019b72d4-a3ea-786d-bd20-56027e23d544" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDistributionsToAffiliates_019b72d4-a3ea-7bcc-8e3c-661205fbe2d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDistributionsToAffiliates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_PaymentsOfDistributionsToAffiliates_019b72d4-a3ea-7bcc-8e3c-661205fbe2d1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromContributionsFromParent_019b72d4-a3ea-7319-8d2f-ceb02599b1a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromContributionsFromParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_ProceedsFromContributionsFromParent_019b72d4-a3ea-7319-8d2f-ceb02599b1a4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_019b72d4-a3ea-7d79-a276-dfb2545ecae3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_019b72d4-a3ea-7d79-a276-dfb2545ecae3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019b72d4-a3ea-7a6d-a315-0925eaed13a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019b72d4-a3ea-7a6d-a315-0925eaed13a9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_019b72d4-a3ea-7633-9f98-0673f60902d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_019b72d4-a3ea-7633-9f98-0673f60902d8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019b72d4-a3ea-7638-8fec-30317c3dcf96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019b72d4-a3ea-7638-8fec-30317c3dcf96" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019b72d4-a3ea-7d8e-ad11-fb98b39c3cb0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019b72d4-a3ea-70d2-b4f8-a945f526e159" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019b72d4-a3ea-7d8e-ad11-fb98b39c3cb0" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019b72d4-a3ea-70a2-b03d-5e395da7aeed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019b72d4-a3ea-70a2-b03d-5e395da7aeed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_019b72d4-a3ea-7d80-b4f3-3ced0530c289" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c7bac-3c4d-7138-8fee-9fd1eb45b3cf" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_019b72d4-a3ea-7d80-b4f3-3ced0530c289" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_019b72d4-a3ea-77ee-b3ca-80174b8d6873" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/ConsolidatedStatementsofCashFlowsParenthetical" xlink:type="simple" xlink:href="lgn-20251231.xsd#ConsolidatedStatementsofCashFlowsParenthetical"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/ConsolidatedStatementsofCashFlowsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019b72d4-a3ea-7222-a146-286e8d10274f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:to="loc_us-gaap_StatementTable_019b72d4-a3ea-7222-a146-286e8d10274f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b72d4-a3ea-7bdc-bd65-f91471e317aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019b72d4-a3ea-7222-a146-286e8d10274f" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b72d4-a3ea-7bdc-bd65-f91471e317aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b72d4-a3ea-7bdc-bd65-f91471e317aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b72d4-a3ea-7bdc-bd65-f91471e317aa" xlink:to="loc_us-gaap_RelatedPartyDomain_019b72d4-a3ea-7bdc-bd65-f91471e317aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b72d4-a3ea-73a5-b159-9730ef730127" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b72d4-a3ea-7bdc-bd65-f91471e317aa" xlink:to="loc_us-gaap_RelatedPartyDomain_019b72d4-a3ea-73a5-b159-9730ef730127" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019b72d4-a3ea-7260-9d43-3c4325825eea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b72d4-a3ea-73a5-b159-9730ef730127" xlink:to="loc_us-gaap_RelatedPartyMember_019b72d4-a3ea-7260-9d43-3c4325825eea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7bb1-85fc-7751-8098-e39526b91782" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019c7bb1-85fc-7751-8098-e39526b91782" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_019b72d4-a3ea-7add-81d7-aea66f2b2549" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_019b72d4-a3ea-7add-81d7-aea66f2b2549" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_019b72d4-a3ea-723e-b08e-a54a43177958" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_019b72d4-a3ea-723e-b08e-a54a43177958" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019b72d4-a3ea-74f5-9c8a-1d7c8ecd9743" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019b72d4-a3ea-76de-b38a-ad6860b72aab" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019b72d4-a3ea-74f5-9c8a-1d7c8ecd9743" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/NatureofOperationsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#NatureofOperationsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/NatureofOperationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfProductInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7d98-8478-b86b2f29b089" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019c99b6-31b4-7474-a9a6-d6d4d8d8fc26" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7d98-8478-b86b2f29b089" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IPOMember_019c99b6-31b4-7a47-8806-b72eaf16ea49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7d98-8478-b86b2f29b089" xlink:to="loc_us-gaap_IPOMember_019c99b6-31b4-7a47-8806-b72eaf16ea49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SecondaryOfferingMember_019c99b6-6c7e-772b-b975-294c7f13a396" xlink:href="lgn-20251231.xsd#lgn_SecondaryOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019c99b6-31b4-7d98-8478-b86b2f29b089" xlink:to="loc_lgn_SecondaryOfferingMember_019c99b6-6c7e-772b-b975-294c7f13a396" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019c99b6-4d40-7b27-bfd1-453c0d6baec8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019c99b6-4d40-7b27-bfd1-453c0d6baec8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c99b6-4d40-7b27-bfd1-453c0d6baec8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c99b6-4d40-7b27-bfd1-453c0d6baec8" xlink:to="loc_us-gaap_ClassOfStockDomain_019c99b6-4d40-7b27-bfd1-453c0d6baec8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019c99b6-4d40-7950-a348-4f09f2455bbb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019c99b6-4d40-7b27-bfd1-453c0d6baec8" xlink:to="loc_us-gaap_ClassOfStockDomain_019c99b6-4d40-7950-a348-4f09f2455bbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019c99b6-4d40-705f-be19-ece319d59143" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019c99b6-4d40-7950-a348-4f09f2455bbb" xlink:to="loc_us-gaap_CommonClassAMember_019c99b6-4d40-705f-be19-ece319d59143" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019c99b6-4d40-7a44-93a4-3f6dd8da72bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019c99b6-4d40-7a44-93a4-3f6dd8da72bf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c99b6-4d40-7a44-93a4-3f6dd8da72bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c99b6-4d40-7a44-93a4-3f6dd8da72bf" xlink:to="loc_us-gaap_EquityComponentDomain_019c99b6-4d40-7a44-93a4-3f6dd8da72bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c99b6-4d40-7a2e-ac94-9fa85eef6486" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c99b6-4d40-7a44-93a4-3f6dd8da72bf" xlink:to="loc_us-gaap_EquityComponentDomain_019c99b6-4d40-7a2e-ac94-9fa85eef6486" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019c99b6-4d40-73b8-a235-8ddde7d9bf81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c99b6-4d40-7a2e-ac94-9fa85eef6486" xlink:to="loc_us-gaap_CommonStockMember_019c99b6-4d40-73b8-a235-8ddde7d9bf81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019c99b6-4d40-7757-8ad8-8eea8119a567" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:to="loc_dei_LegalEntityAxis_019c99b6-4d40-7757-8ad8-8eea8119a567" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019c99b6-4d40-7757-8ad8-8eea8119a567_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019c99b6-4d40-7757-8ad8-8eea8119a567" xlink:to="loc_dei_EntityDomain_019c99b6-4d40-7757-8ad8-8eea8119a567_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019c99b6-4d40-7549-85cd-d1cdc513c38a" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019c99b6-4d40-7757-8ad8-8eea8119a567" xlink:to="loc_dei_EntityDomain_019c99b6-4d40-7549-85cd-d1cdc513c38a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceParentIILLCMember_019c99b6-4d40-758a-8e6b-8080602c5577" xlink:href="lgn-20251231.xsd#lgn_LegenceParentIILLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019c99b6-4d40-7549-85cd-d1cdc513c38a" xlink:to="loc_lgn_LegenceParentIILLCMember_019c99b6-4d40-758a-8e6b-8080602c5577" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceParentMember_019c99b6-4d40-7da5-a888-7cfd5a9ee18e" xlink:href="lgn-20251231.xsd#lgn_LegenceParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019c99b6-4d40-7549-85cd-d1cdc513c38a" xlink:to="loc_lgn_LegenceParentMember_019c99b6-4d40-7da5-a888-7cfd5a9ee18e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019c99b6-4d40-767d-a82d-cfe68c6f0474" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_019c4718-9db2-7f83-b5c0-a961a9361f77" xlink:to="loc_srt_OwnershipAxis_019c99b6-4d40-767d-a82d-cfe68c6f0474" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019c99b6-4d40-767d-a82d-cfe68c6f0474_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019c99b6-4d40-767d-a82d-cfe68c6f0474" xlink:to="loc_srt_OwnershipDomain_019c99b6-4d40-767d-a82d-cfe68c6f0474_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019c99b6-4d40-7c81-8104-03c90728c1da" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019c99b6-4d40-767d-a82d-cfe68c6f0474" xlink:to="loc_srt_OwnershipDomain_019c99b6-4d40-7c81-8104-03c90728c1da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceIntermediateMember_019c99b6-4d40-7797-9a49-6cc155e9917b" xlink:href="lgn-20251231.xsd#lgn_LegenceIntermediateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019c99b6-4d40-7c81-8104-03c90728c1da" xlink:to="loc_lgn_LegenceIntermediateMember_019c99b6-4d40-7797-9a49-6cc155e9917b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019c99b6-31b4-723e-8fed-d410300a9d80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019c99b6-31b4-723e-8fed-d410300a9d80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_019c99b6-31b4-7484-b9d6-fcc2a3133594" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_019c99b6-31b4-7484-b9d6-fcc2a3133594" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019c99b6-31b4-78df-8f99-4401cd99dd26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019c99b6-31b4-78df-8f99-4401cd99dd26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_StockIssuedDuringPeriodSharesEffectOfReorganization_019c99b6-4d41-7a20-8b08-8860663488b3" xlink:href="lgn-20251231.xsd#lgn_StockIssuedDuringPeriodSharesEffectOfReorganization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_lgn_StockIssuedDuringPeriodSharesEffectOfReorganization_019c99b6-4d41-7a20-8b08-8860663488b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019c99b6-4d41-7ec9-99a3-7754a881f909" xlink:href="lgn-20251231.xsd#lgn_LimitedPartnersCapitalUnitConversionRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019c99b6-4d41-7ec9-99a3-7754a881f909" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019c99b6-4d41-7f2d-aa22-34e51652aae0" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsOwed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019c99b6-4d41-7f2d-aa22-34e51652aae0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019c99b6-4d41-7411-9a19-a689692e90e5" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsRetained"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_019c4719-915a-7dfb-b8c8-dad4d763a194" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019c99b6-4d41-7411-9a19-a689692e90e5" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#SummaryofSignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b43e2-e4ca-7ea4-88fd-2cffb4e6b23a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b43e2-e4ca-7ea4-88fd-2cffb4e6b23a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019c99dc-0238-7598-ae45-4ac2ab49c39e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b43e2-e4ca-7ea4-88fd-2cffb4e6b23a" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019c99dc-0238-7598-ae45-4ac2ab49c39e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c99dc-0238-7598-ae45-4ac2ab49c39e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c99dc-0238-7598-ae45-4ac2ab49c39e" xlink:to="loc_us-gaap_SegmentDomain_019c99dc-0238-7598-ae45-4ac2ab49c39e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c99dc-0238-74ed-a604-ceefd70c23e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c99dc-0238-7598-ae45-4ac2ab49c39e" xlink:to="loc_us-gaap_SegmentDomain_019c99dc-0238-74ed-a604-ceefd70c23e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringAndConsultingMember_019c99dc-0238-7623-bf26-701767ebf7a6" xlink:href="lgn-20251231.xsd#lgn_EngineeringAndConsultingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c99dc-0238-74ed-a604-ceefd70c23e0" xlink:to="loc_lgn_EngineeringAndConsultingMember_019c99dc-0238-7623-bf26-701767ebf7a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b43e2-e4ca-7736-9157-5c9b4582b9f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b43e2-e4ca-7ea4-88fd-2cffb4e6b23a" xlink:to="loc_us-gaap_AwardTypeAxis_019b43e2-e4ca-7736-9157-5c9b4582b9f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7736-9157-5c9b4582b9f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b43e2-e4ca-7736-9157-5c9b4582b9f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7736-9157-5c9b4582b9f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7987-935a-71ca40d06228" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b43e2-e4ca-7736-9157-5c9b4582b9f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7987-935a-71ca40d06228" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TimeInterestsMember_019b43e2-e4ca-7371-b3f3-d2e150a8d329" xlink:href="lgn-20251231.xsd#lgn_TimeInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7987-935a-71ca40d06228" xlink:to="loc_lgn_TimeInterestsMember_019b43e2-e4ca-7371-b3f3-d2e150a8d329" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PerformanceInterestsMember_019b43e2-e4ca-7c38-80e6-60a557e85f04" xlink:href="lgn-20251231.xsd#lgn_PerformanceInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7987-935a-71ca40d06228" xlink:to="loc_lgn_PerformanceInterestsMember_019b43e2-e4ca-7c38-80e6-60a557e85f04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ExitInterestsMember_019b43e2-e4ca-7594-afbe-03afda982f20" xlink:href="lgn-20251231.xsd#lgn_ExitInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b43e2-e4ca-7987-935a-71ca40d06228" xlink:to="loc_lgn_ExitInterestsMember_019b43e2-e4ca-7594-afbe-03afda982f20" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashCurrent_019d09eb-ce49-7303-81b0-1694b1bc1ed6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_RestrictedCashCurrent_019d09eb-ce49-7303-81b0-1694b1bc1ed6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredOfferingCosts_019b43da-8f88-7a9d-9c8f-36887ac0e52d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredOfferingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_DeferredOfferingCosts_019b43da-8f88-7a9d-9c8f-36887ac0e52d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ReportingUnitFairValueInExcessOfCarryingAmountNumber_019c99dc-0238-78c2-9e6e-226274060ea1" xlink:href="lgn-20251231.xsd#lgn_ReportingUnitFairValueInExcessOfCarryingAmountNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_ReportingUnitFairValueInExcessOfCarryingAmountNumber_019c99dc-0238-78c2-9e6e-226274060ea1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ReportingUnitCarryingAmountInExcessOfFairValueNumber_019d2520-cf2f-7973-a31d-ce3d4e5e2277" xlink:href="lgn-20251231.xsd#lgn_ReportingUnitCarryingAmountInExcessOfFairValueNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_ReportingUnitCarryingAmountInExcessOfFairValueNumber_019d2520-cf2f-7973-a31d-ce3d4e5e2277" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d1d14-6285-7b3a-8b98-76e307c1868a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d1d14-6285-7b3a-8b98-76e307c1868a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentage_019cdc30-f6a5-712d-b17f-a315dddbeecb" xlink:href="lgn-20251231.xsd#lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentage_019cdc30-f6a5-712d-b17f-a315dddbeecb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019b43e2-e4ca-7b17-8020-7faf7ab1853b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019b43e2-e4ca-7b17-8020-7faf7ab1853b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardUnvestedRestrictedStockDistributionRepaymentUponTerminationPeriod_019b43e0-d5f8-7a9b-8f3d-e5a350bde6ae" xlink:href="lgn-20251231.xsd#lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardUnvestedRestrictedStockDistributionRepaymentUponTerminationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardUnvestedRestrictedStockDistributionRepaymentUponTerminationPeriod_019b43e0-d5f8-7a9b-8f3d-e5a350bde6ae" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019cdc32-f311-71ab-8aa8-959e79f75204" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019cdc32-f311-71ab-8aa8-959e79f75204" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019c7c7f-02ed-7ab7-8431-9a055d69516b" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsOwed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019c7c7f-02ed-7ab7-8431-9a055d69516b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019c7c7f-8cf5-7c5b-a379-af0898562f25" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsRetained"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b43e2-e4ca-76a0-90ae-b81673fa6a52" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019c7c7f-8cf5-7c5b-a379-af0898562f25" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/SummaryofSignificantAccountingPoliciesScheduleofEstimatedUsefulLivesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#SummaryofSignificantAccountingPoliciesScheduleofEstimatedUsefulLivesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/SummaryofSignificantAccountingPoliciesScheduleofEstimatedUsefulLivesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b43d6-90de-7cbf-a359-318e427fd394" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b43d6-90de-7088-97e1-a60345ff824f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b43d6-90de-7cbf-a359-318e427fd394" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b43d6-90de-7088-97e1-a60345ff824f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b43d6-b686-71a1-b247-6f0b6582fb99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b43d6-90de-7088-97e1-a60345ff824f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b43d6-b686-71a1-b247-6f0b6582fb99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-71a1-b247-6f0b6582fb99_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b43d6-b686-71a1-b247-6f0b6582fb99" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-71a1-b247-6f0b6582fb99_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b43d6-b686-71a1-b247-6f0b6582fb99" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_019be1b8-65fe-72e8-b61e-0a88dc6ee024" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:to="loc_us-gaap_VehiclesMember_019be1b8-65fe-72e8-b61e-0a88dc6ee024" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ComputerEquipmentAndSoftwareMember_019bc2e5-e2d9-717c-8c4c-7c0cc0d7391a" xlink:href="lgn-20251231.xsd#lgn_ComputerEquipmentAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:to="loc_lgn_ComputerEquipmentAndSoftwareMember_019bc2e5-e2d9-717c-8c4c-7c0cc0d7391a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_019bc2db-f91d-7bb1-96d4-d36bc2f095fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_019bc2db-f91d-7bb1-96d4-d36bc2f095fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019b43d8-5cf7-7abf-b52f-7cdc73b151a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b43d6-b686-7162-9cb0-c83dd4756df8" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019b43d8-5cf7-7abf-b52f-7cdc73b151a9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019c4727-49e4-70df-87c8-3856bd8c8b0d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b43d6-90de-7088-97e1-a60345ff824f" xlink:to="loc_srt_RangeAxis_019c4727-49e4-70df-87c8-3856bd8c8b0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c4727-49e4-70df-87c8-3856bd8c8b0d_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019c4727-49e4-70df-87c8-3856bd8c8b0d" xlink:to="loc_srt_RangeMember_019c4727-49e4-70df-87c8-3856bd8c8b0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c4727-7367-7254-ac59-5f384419f8e9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019c4727-49e4-70df-87c8-3856bd8c8b0d" xlink:to="loc_srt_RangeMember_019c4727-7367-7254-ac59-5f384419f8e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019c4727-9600-75af-8802-7dbfc54da343" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c4727-7367-7254-ac59-5f384419f8e9" xlink:to="loc_srt_MinimumMember_019c4727-9600-75af-8802-7dbfc54da343" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019c4727-bb09-718e-968c-6ee9e539a714" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c4727-7367-7254-ac59-5f384419f8e9" xlink:to="loc_srt_MaximumMember_019c4727-bb09-718e-968c-6ee9e539a714" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_019b43d6-90de-78c9-8cb2-1af40ddd0b1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b43d6-90de-7cbf-a359-318e427fd394" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_019b43d6-90de-78c9-8cb2-1af40ddd0b1b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-7573-9251-9059c5a7acf4_default" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:to="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-7573-9251-9059c5a7acf4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:to="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_OutputMethodMember_019b43e5-8b3c-72a9-b6f8-75a4b91855ad" xlink:href="lgn-20251231.xsd#lgn_OutputMethodMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:to="loc_lgn_OutputMethodMember_019b43e5-8b3c-72a9-b6f8-75a4b91855ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-71d3-825d-41f1cf9ae465_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-71d3-825d-41f1cf9ae465_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019b43e5-8b3c-73cf-b038-e5d9e203c742" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019b43e5-8b3c-73cf-b038-e5d9e203c742" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-783b-bb31-30be1f775502_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-783b-bb31-30be1f775502_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodRiskMember_019b43e5-8b3c-7571-a435-faa5dbc97a2f" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:to="loc_lgn_RevenueRecognitionMethodRiskMember_019b43e5-8b3c-7571-a435-faa5dbc97a2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019b43e5-8b3c-7c2e-9e50-9e17594a854d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019b43e5-8b3c-7c2e-9e50-9e17594a854d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019b43e5-8b3c-7c20-aec9-18f1da034617" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019b43e5-8b3c-7c20-aec9-18f1da034617" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions_019b43e5-8b3c-713d-be07-5e63e3f3dd1c" xlink:href="lgn-20251231.xsd#lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions_019b43e5-8b3c-713d-be07-5e63e3f3dd1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5e3-9eaa-7ce4-b5f3-8569da6e2a07" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5e3-9eaa-7ce4-b5f3-8569da6e2a07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5ec-fc55-76b2-8359-b23966bd443f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5ec-fc55-76b2-8359-b23966bd443f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019b43e5-8b3c-7387-8a95-841459ef5b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019b43e5-8b3c-7387-8a95-841459ef5b1a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ContractsReceivableRetentions_019b43e5-8b3c-7621-9ad7-bf29e42bb8b3" xlink:href="lgn-20251231.xsd#lgn_ContractsReceivableRetentions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_lgn_ContractsReceivableRetentions_019b43e5-8b3c-7621-9ad7-bf29e42bb8b3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019b43e5-8b3c-7a52-af7e-8f4c48bf8543" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019b43e5-8b3c-7a52-af7e-8f4c48bf8543" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019b43e5-8b3c-78fc-ae64-24d78242ea7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019b43e5-8b3c-78fc-ae64-24d78242ea7a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019b43e5-8b3c-70da-8958-8a7f8f0abb59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019b43e5-8b3c-70da-8958-8a7f8f0abb59" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails_1" xlink:type="simple" xlink:href="lgn-20251231.xsd#RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-7573-9251-9059c5a7acf4_default" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:to="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-7573-9251-9059c5a7acf4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lgn_RevenueRecognitionMethodAxis_019b43e5-8b3c-7573-9251-9059c5a7acf4" xlink:to="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_OutputMethodMember_019b43e5-8b3c-72a9-b6f8-75a4b91855ad" xlink:href="lgn-20251231.xsd#lgn_OutputMethodMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_RevenueRecognitionMethodDomain_019b43e5-8b3c-77ef-ae82-293e23132577" xlink:to="loc_lgn_OutputMethodMember_019b43e5-8b3c-72a9-b6f8-75a4b91855ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-71d3-825d-41f1cf9ae465_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-71d3-825d-41f1cf9ae465_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019b43e5-8b3c-71d3-825d-41f1cf9ae465" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019b43e5-8b3c-73cf-b038-e5d9e203c742" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019b43e5-8b3c-74b1-b33c-a4f03d34addc" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019b43e5-8b3c-73cf-b038-e5d9e203c742" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7287-887c-97ee8d7a37eb" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-783b-bb31-30be1f775502_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-783b-bb31-30be1f775502_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019b43e5-8b3c-783b-bb31-30be1f775502" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RevenueRecognitionMethodRiskMember_019b43e5-8b3c-7571-a435-faa5dbc97a2f" xlink:href="lgn-20251231.xsd#lgn_RevenueRecognitionMethodRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019b43e5-8b3c-7f80-8e97-adbe204fad5a" xlink:to="loc_lgn_RevenueRecognitionMethodRiskMember_019b43e5-8b3c-7571-a435-faa5dbc97a2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019b43e5-8b3c-7c20-aec9-18f1da034617" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019b43e5-8b3c-7c20-aec9-18f1da034617" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions_019b43e5-8b3c-713d-be07-5e63e3f3dd1c" xlink:href="lgn-20251231.xsd#lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_lgn_ContractWithCustomerAssetAfterAllowanceForCreditLossRetentions_019b43e5-8b3c-713d-be07-5e63e3f3dd1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5e3-9eaa-7ce4-b5f3-8569da6e2a07" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5e3-9eaa-7ce4-b5f3-8569da6e2a07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5ec-fc55-76b2-8359-b23966bd443f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_019be5ec-fc55-76b2-8359-b23966bd443f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019b43e5-8b3c-7387-8a95-841459ef5b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019b43e5-8b3c-7387-8a95-841459ef5b1a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ContractsReceivableRetentions_019b43e5-8b3c-7621-9ad7-bf29e42bb8b3" xlink:href="lgn-20251231.xsd#lgn_ContractsReceivableRetentions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_lgn_ContractsReceivableRetentions_019b43e5-8b3c-7621-9ad7-bf29e42bb8b3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019b43e5-8b3c-7a52-af7e-8f4c48bf8543" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019b43e5-8b3c-7a52-af7e-8f4c48bf8543" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019b43e5-8b3c-78fc-ae64-24d78242ea7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019b43e5-8b3c-78fc-ae64-24d78242ea7a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019b43e5-8b3c-70da-8958-8a7f8f0abb59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7ca1-b0ca-ac2aa6044e68" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019b43e5-8b3c-70da-8958-8a7f8f0abb59" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsScheduleofDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#RevenueRecognitionandRelatedBalanceSheetAccountsScheduleofDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/RevenueRecognitionandRelatedBalanceSheetAccountsScheduleofDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7baa-a5bb-daa75f948073" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7d13-a046-2093ea31f768" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7baa-a5bb-daa75f948073" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7d13-a046-2093ea31f768" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019b43e5-8b3c-7954-8d92-73c639a59f7b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7d13-a046-2093ea31f768" xlink:to="loc_srt_ProductOrServiceAxis_019b43e5-8b3c-7954-8d92-73c639a59f7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7954-8d92-73c639a59f7b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019b43e5-8b3c-7954-8d92-73c639a59f7b" xlink:to="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7954-8d92-73c639a59f7b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019b43e5-8b3c-7954-8d92-73c639a59f7b" xlink:to="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringAndDesignMember_019b43e5-8b3c-7948-be44-e22daa0d6cad" xlink:href="lgn-20251231.xsd#lgn_EngineeringAndDesignMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:to="loc_lgn_EngineeringAndDesignMember_019b43e5-8b3c-7948-be44-e22daa0d6cad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ProgramAndProjectManagementMember_019b43e5-8b3c-70fc-b70b-3ea1f38a4da2" xlink:href="lgn-20251231.xsd#lgn_ProgramAndProjectManagementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:to="loc_lgn_ProgramAndProjectManagementMember_019b43e5-8b3c-70fc-b70b-3ea1f38a4da2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InstallationAndFabricationMember_019b43e5-8b3c-7342-9493-29ff9b962e5a" xlink:href="lgn-20251231.xsd#lgn_InstallationAndFabricationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:to="loc_lgn_InstallationAndFabricationMember_019b43e5-8b3c-7342-9493-29ff9b962e5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_MaintenanceAndServiceMember_019b43e5-8b3c-786a-b192-0ffdb30d0d26" xlink:href="lgn-20251231.xsd#lgn_MaintenanceAndServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019b43e5-8b3c-7436-9c65-66e581404e2e" xlink:to="loc_lgn_MaintenanceAndServiceMember_019b43e5-8b3c-786a-b192-0ffdb30d0d26" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019b43e5-8b3c-7733-86f5-60e11d2b3a8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019b43e5-8b3c-7d13-a046-2093ea31f768" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019b43e5-8b3c-7733-86f5-60e11d2b3a8c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7733-86f5-60e11d2b3a8c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b43e5-8b3c-7733-86f5-60e11d2b3a8c" xlink:to="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7733-86f5-60e11d2b3a8c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7805-a936-fb8aa5687a21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b43e5-8b3c-7733-86f5-60e11d2b3a8c" xlink:to="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7805-a936-fb8aa5687a21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringAndConsultingMember_019b43e5-8b3c-7254-8483-777d30d4ce4f" xlink:href="lgn-20251231.xsd#lgn_EngineeringAndConsultingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7805-a936-fb8aa5687a21" xlink:to="loc_lgn_EngineeringAndConsultingMember_019b43e5-8b3c-7254-8483-777d30d4ce4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InstallationAndMaintenanceMember_019b43e5-8b3c-7ab4-8da6-1b839f3c4366" xlink:href="lgn-20251231.xsd#lgn_InstallationAndMaintenanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b43e5-8b3c-7805-a936-fb8aa5687a21" xlink:to="loc_lgn_InstallationAndMaintenanceMember_019b43e5-8b3c-7ab4-8da6-1b839f3c4366" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b43e5-8b3c-736a-baf9-30e96e3252c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019b43e5-8b3c-7baa-a5bb-daa75f948073" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b43e5-8b3c-736a-baf9-30e96e3252c2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/AcquisitionsScheduleofConsiderationTransferredDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#AcquisitionsScheduleofConsiderationTransferredDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/AcquisitionsScheduleofConsiderationTransferredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-7295-a043-a571f89d54d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-7295-a043-a571f89d54d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-76ff-8a5a-8248f651a74c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-7295-a043-a571f89d54d3" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-76ff-8a5a-8248f651a74c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-76ff-8a5a-8248f651a74c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-76ff-8a5a-8248f651a74c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-76ff-8a5a-8248f651a74c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-76ff-8a5a-8248f651a74c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IMDMember_019c473e-1f16-7131-b144-5996f85016a4" xlink:href="lgn-20251231.xsd#lgn_IMDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_IMDMember_019c473e-1f16-7131-b144-5996f85016a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2025AcquisitionMember_019c99c7-2db4-7ede-b73c-ecd58b85b15a" xlink:href="lgn-20251231.xsd#lgn_Other2025AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Other2025AcquisitionMember_019c99c7-2db4-7ede-b73c-ecd58b85b15a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2025AcquisitionsMember_019c473f-8110-7530-94b9-226998a0d9b0" xlink:href="lgn-20251231.xsd#lgn_Total2025AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Total2025AcquisitionsMember_019c473f-8110-7530-94b9-226998a0d9b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TheBowersGroupInc.Member_019cdc41-4e2b-7bf8-839b-815d05347600" xlink:href="lgn-20251231.xsd#lgn_TheBowersGroupInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_TheBowersGroupInc.Member_019cdc41-4e2b-7bf8-839b-815d05347600" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_MetrixEngineersLLCMember_019d09f1-b9e7-704b-aa58-3cd75e4aa747" xlink:href="lgn-20251231.xsd#lgn_MetrixEngineersLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_MetrixEngineersLLCMember_019d09f1-b9e7-704b-aa58-3cd75e4aa747" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2026AcquisitionsMember_019d0a06-d20a-7da2-b893-a27b65fdbd5a" xlink:href="lgn-20251231.xsd#lgn_Total2026AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Total2026AcquisitionsMember_019d0a06-d20a-7da2-b893-a27b65fdbd5a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_P2SLPMember_019b7ce4-0b1a-7ab8-9121-ea60c5b5fef1" xlink:href="lgn-20251231.xsd#lgn_P2SLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_P2SLPMember_019b7ce4-0b1a-7ab8-9121-ea60c5b5fef1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b7ce4-0b1a-771e-86bf-3d5948b95ef7" xlink:href="lgn-20251231.xsd#lgn_AMAConsultingEngineersHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b7ce4-0b1a-771e-86bf-3d5948b95ef7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2024AcquisitionMember_019b7ce4-0b1a-7264-b75f-1a579b5363d3" xlink:href="lgn-20251231.xsd#lgn_Other2024AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Other2024AcquisitionMember_019b7ce4-0b1a-7264-b75f-1a579b5363d3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2024AcquisitionsMember_019b9925-8f06-76da-b4da-62f65383cbab" xlink:href="lgn-20251231.xsd#lgn_Total2024AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Total2024AcquisitionsMember_019b9925-8f06-76da-b4da-62f65383cbab" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SanJoseBoilerWorksInc.Member_019b8c76-ac23-7c38-ad03-817041889c73" xlink:href="lgn-20251231.xsd#lgn_SanJoseBoilerWorksInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_SanJoseBoilerWorksInc.Member_019b8c76-ac23-7c38-ad03-817041889c73" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A.O.ReedCo.Member_019b8c77-8164-7ac3-ada4-bdb7118742cb" xlink:href="lgn-20251231.xsd#lgn_A.O.ReedCo.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_A.O.ReedCo.Member_019b8c77-8164-7ac3-ada4-bdb7118742cb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_OCIAssociatesLLCMember_019b8c78-07f9-760a-bdb3-26b905313805" xlink:href="lgn-20251231.xsd#lgn_OCIAssociatesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_OCIAssociatesLLCMember_019b8c78-07f9-760a-bdb3-26b905313805" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2023AcquisitionMember_019b8c79-0231-7ace-9a5c-66fce1dc420e" xlink:href="lgn-20251231.xsd#lgn_Other2023AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Other2023AcquisitionMember_019b8c79-0231-7ace-9a5c-66fce1dc420e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2023AcquisitionsMember_019c4757-2647-79bd-9396-e2a858eff56e" xlink:href="lgn-20251231.xsd#lgn_Total2023AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-75fe-b069-38f53b471539" xlink:to="loc_lgn_Total2023AcquisitionsMember_019c4757-2647-79bd-9396-e2a858eff56e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cb8e9-3d76-7e43-94ba-78536394abae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-7295-a043-a571f89d54d3" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cb8e9-3d76-7e43-94ba-78536394abae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8e9-3d76-7e43-94ba-78536394abae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8e9-3d76-7e43-94ba-78536394abae" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8e9-3d76-7e43-94ba-78536394abae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8e9-3d76-7ea5-9c47-22bee53443a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8e9-3d76-7e43-94ba-78536394abae" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8e9-3d76-7ea5-9c47-22bee53443a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cb8e9-60b0-7432-9a22-5e0eae51c15b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cb8e9-3d76-7ea5-9c47-22bee53443a1" xlink:to="loc_us-gaap_SubsequentEventMember_019cb8e9-60b0-7432-9a22-5e0eae51c15b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_019b7ce4-0b1a-7c37-82f9-9d93ef5dce76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_019b7ce4-0b1a-7c37-82f9-9d93ef5dce76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019b7ce4-0b1a-7712-9ea9-9266ee656dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019b7ce4-0b1a-7712-9ea9-9266ee656dc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationConsiderationTransferredDeferredConsideration_019cb901-a107-7069-8880-40f0c82d9704" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationConsiderationTransferredDeferredConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_lgn_BusinessCombinationConsiderationTransferredDeferredConsideration_019cb901-a107-7069-8880-40f0c82d9704" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationContingentConsiderationEarnout_019b9839-f137-75da-8995-91bfceeac9f0" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationContingentConsiderationEarnout"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_lgn_BusinessCombinationContingentConsiderationEarnout_019b9839-f137-75da-8995-91bfceeac9f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_019b7ce4-0b1a-7aab-ba3e-709426ec260b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_019b7ce4-0b1a-7aab-ba3e-709426ec260b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationConsiderationTransferredPromissoryNotesDueToSeller_019be120-7a1d-7f93-9226-3132ee1d85e5" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationConsiderationTransferredPromissoryNotesDueToSeller"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_lgn_BusinessCombinationConsiderationTransferredPromissoryNotesDueToSeller_019be120-7a1d-7f93-9226-3132ee1d85e5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationConsiderationTransferredPurchasePriceReceivablePayable_019b985c-d8cd-7eeb-a9f9-2391dab80c2f" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationConsiderationTransferredPurchasePriceReceivablePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_lgn_BusinessCombinationConsiderationTransferredPurchasePriceReceivablePayable_019b985c-d8cd-7eeb-a9f9-2391dab80c2f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019b7ce4-0b1a-7dfc-88db-590b35111535" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7b42-a13e-ecd6066a90fb" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019b7ce4-0b1a-7dfc-88db-590b35111535" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/AcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#AcquisitionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/AcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019cb8fc-dce1-7127-9e4f-a9f86895e163" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019cb8fc-dce1-7127-9e4f-a9f86895e163" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7127-9e4f-a9f86895e163_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019cb8fc-dce1-7127-9e4f-a9f86895e163" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7127-9e4f-a9f86895e163_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019cb8fc-dce1-7127-9e4f-a9f86895e163" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A2025AcquisitionsMember_019cb8fc-dce1-7373-b044-d7ef4a8c2486" xlink:href="lgn-20251231.xsd#lgn_A2025AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_A2025AcquisitionsMember_019cb8fc-dce1-7373-b044-d7ef4a8c2486" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TheBowersGroupInc.Member_019cf4a0-aed6-7da5-9741-17d27b1eb230" xlink:href="lgn-20251231.xsd#lgn_TheBowersGroupInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_TheBowersGroupInc.Member_019cf4a0-aed6-7da5-9741-17d27b1eb230" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_P2SLPMember_019cb8fd-9e60-7a6a-9112-88417bc417e5" xlink:href="lgn-20251231.xsd#lgn_P2SLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_P2SLPMember_019cb8fd-9e60-7a6a-9112-88417bc417e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2024AcquisitionMember_019cb8fd-9e60-7c5a-a1a5-69dc1b35dbb7" xlink:href="lgn-20251231.xsd#lgn_Other2024AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_Other2024AcquisitionMember_019cb8fd-9e60-7c5a-a1a5-69dc1b35dbb7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019cb8fd-c0c1-7fe7-974b-eb3acd7c87b0" xlink:href="lgn-20251231.xsd#lgn_AMAConsultingEngineersHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019cb8fd-c0c1-7fe7-974b-eb3acd7c87b0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SanJoseBoilerWorksInc.Member_019cb8fd-e2cc-79e9-bcdd-fff380262915" xlink:href="lgn-20251231.xsd#lgn_SanJoseBoilerWorksInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_SanJoseBoilerWorksInc.Member_019cb8fd-e2cc-79e9-bcdd-fff380262915" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A.O.ReedCo.Member_019cb8fe-0fe5-7ed2-b6c8-cb04bd649790" xlink:href="lgn-20251231.xsd#lgn_A.O.ReedCo.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_A.O.ReedCo.Member_019cb8fe-0fe5-7ed2-b6c8-cb04bd649790" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_OCIAssociatesLLCMember_019cb8fe-0fe5-7461-ad27-f4c9600adac9" xlink:href="lgn-20251231.xsd#lgn_OCIAssociatesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_OCIAssociatesLLCMember_019cb8fe-0fe5-7461-ad27-f4c9600adac9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2023AcquisitionMember_019cb8fe-0fe5-7a71-8585-ac9e1a86a03e" xlink:href="lgn-20251231.xsd#lgn_Other2023AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_Other2023AcquisitionMember_019cb8fe-0fe5-7a71-8585-ac9e1a86a03e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_MetrixEngineersLLCMember_019d1e5a-138b-7561-aa1e-1eaaa1fd8658" xlink:href="lgn-20251231.xsd#lgn_MetrixEngineersLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cb8fc-dce1-7ea0-bf61-90c620ed3637" xlink:to="loc_lgn_MetrixEngineersLLCMember_019d1e5a-138b-7561-aa1e-1eaaa1fd8658" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cb8fd-526f-7cc6-8302-05c90cc8415b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cb8fd-526f-7cc6-8302-05c90cc8415b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8fd-526f-7cc6-8302-05c90cc8415b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8fd-526f-7cc6-8302-05c90cc8415b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8fd-526f-7cc6-8302-05c90cc8415b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8fd-526f-7001-992d-40cf44c0c86b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8fd-526f-7cc6-8302-05c90cc8415b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8fd-526f-7001-992d-40cf44c0c86b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cb8fd-526f-78ef-ac0a-778bde1be076" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cb8fd-526f-7001-992d-40cf44c0c86b" xlink:to="loc_us-gaap_SubsequentEventMember_019cb8fd-526f-78ef-ac0a-778bde1be076" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019cb8fd-526f-70b3-b010-6a7b20e55a46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:to="loc_us-gaap_DebtInstrumentAxis_019cb8fd-526f-70b3-b010-6a7b20e55a46" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-70b3-b010-6a7b20e55a46_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cb8fd-526f-70b3-b010-6a7b20e55a46" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-70b3-b010-6a7b20e55a46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cb8fd-526f-70b3-b010-6a7b20e55a46" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IncrementalTermLoanMember_019cb8fd-526f-7579-8fc3-c8cd9e1285ba" xlink:href="lgn-20251231.xsd#lgn_IncrementalTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:to="loc_lgn_IncrementalTermLoanMember_019cb8fd-526f-7579-8fc3-c8cd9e1285ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember_019cb8fd-e2cc-715e-8782-bc31b45bd282" xlink:href="lgn-20251231.xsd#lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:to="loc_lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember_019cb8fd-e2cc-715e-8782-bc31b45bd282" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NotePayableThreeYearMember_019cb8fd-e2cc-71e3-ad3b-d07617c15caa" xlink:href="lgn-20251231.xsd#lgn_NotePayableThreeYearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:to="loc_lgn_NotePayableThreeYearMember_019cb8fd-e2cc-71e3-ad3b-d07617c15caa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NotePayableLessThanTwoYearMember_019cb8fd-e2cc-7284-8e9b-ce12272d0022" xlink:href="lgn-20251231.xsd#lgn_NotePayableLessThanTwoYearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cb8fd-526f-7d81-a1be-c82372b234dc" xlink:to="loc_lgn_NotePayableLessThanTwoYearMember_019cb8fd-e2cc-7284-8e9b-ce12272d0022" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cb8fd-526f-7842-b364-3c86abfc7764" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-715a-afe3-81ffb6511d21" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cb8fd-526f-7842-b364-3c86abfc7764" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7842-b364-3c86abfc7764_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cb8fd-526f-7842-b364-3c86abfc7764" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7842-b364-3c86abfc7764_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7f6d-890a-634da9b3210d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cb8fd-526f-7842-b364-3c86abfc7764" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7f6d-890a-634da9b3210d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019cb8fd-526f-767e-b9e6-81afba8f6520" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7f6d-890a-634da9b3210d" xlink:to="loc_us-gaap_SecuredDebtMember_019cb8fd-526f-767e-b9e6-81afba8f6520" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019cb8fd-e2cc-7067-9ddb-6a8b5e3cbb1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cb8fd-526f-7f6d-890a-634da9b3210d" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019cb8fd-e2cc-7067-9ddb-6a8b5e3cbb1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_019cb8fc-dce1-7548-9851-0a33d3bbf649" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_019cb8fc-dce1-7548-9851-0a33d3bbf649" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationConsiderationTransferredLiabilitiesIncurredHoldback_019cb8fc-dce1-709c-89eb-4aa4fa84b649" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationConsiderationTransferredLiabilitiesIncurredHoldback"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_lgn_BusinessCombinationConsiderationTransferredLiabilitiesIncurredHoldback_019cb8fc-dce1-709c-89eb-4aa4fa84b649" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019cb8fd-0717-7913-93e4-222f9f8c795b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019cb8fd-0717-7913-93e4-222f9f8c795b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019cb8fd-526f-748a-a2a1-8649be693e0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019cb8fd-526f-748a-a2a1-8649be693e0f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019cb8fd-c0c1-7746-9891-0e086bd3cd7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019cb8fd-c0c1-7746-9891-0e086bd3cd7c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_019cb8fd-c0c1-73d4-a615-07f6c86b084a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_019cb8fd-c0c1-73d4-a615-07f6c86b084a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_019d1d1f-b9ca-79ff-871f-046c0191b030" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_019d1d1f-b9ca-79ff-871f-046c0191b030" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019cb8fd-e2cc-7f1c-88d0-694a26f2f654" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019cb8fd-e2cc-7f1c-88d0-694a26f2f654" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_019cb8fd-e2cc-7b60-95ea-818c7bb3658f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_DebtInstrumentTerm_019cb8fd-e2cc-7b60-95ea-818c7bb3658f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cb8fd-e2cc-7857-ac6b-2753e43af7b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cb8fd-e2cc-7857-ac6b-2753e43af7b4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_019cb8fd-e2cc-7b30-b26e-ffccc87c9f8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_DebtInstrumentFairValue_019cb8fd-e2cc-7b30-b26e-ffccc87c9f8c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019cf78e-4171-7ae1-935a-cf9fcfddbb2a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019cf78e-4171-7ae1-935a-cf9fcfddbb2a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019cf78f-aae6-7089-9d49-7635842d212a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019cf78f-aae6-7089-9d49-7635842d212a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount_019cb8fe-0fe5-7c5e-a1e1-cc90fe2de01e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount_019cb8fe-0fe5-7c5e-a1e1-cc90fe2de01e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_019cb8fe-6a15-7cb2-937c-d2935a8e6d81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_019cb8fe-6a15-7cb2-937c-d2935a8e6d81" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_019cb8fe-6a15-76b4-977d-d7f7d4cdf5de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_019cb8fe-6a15-76b4-977d-d7f7d4cdf5de" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019ce342-e85d-7d13-aab2-76fd3b50720f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationBargainPurchaseGainRecognizedStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7161-b195-79c4e5393c5a" xlink:to="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019ce342-e85d-7d13-aab2-76fd3b50720f" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/AcquisitionsScheduleofAssetandLiabilitiesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#AcquisitionsScheduleofAssetandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/AcquisitionsScheduleofAssetandLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7ddf-a7bb-707aab054353" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-75e9-ac5d-a2c91778acaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7ddf-a7bb-707aab054353" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-75e9-ac5d-a2c91778acaa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-7510-8a92-0fca22028212" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-75e9-ac5d-a2c91778acaa" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-7510-8a92-0fca22028212" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7510-8a92-0fca22028212_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-7510-8a92-0fca22028212" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7510-8a92-0fca22028212_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b7ce4-0b1a-7510-8a92-0fca22028212" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IMDMember_019c4747-efe7-78e6-bd00-4496b17c846b" xlink:href="lgn-20251231.xsd#lgn_IMDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_IMDMember_019c4747-efe7-78e6-bd00-4496b17c846b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2025AcquisitionMember_019c99d5-7631-726c-a364-1e198120694a" xlink:href="lgn-20251231.xsd#lgn_Other2025AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_Other2025AcquisitionMember_019c99d5-7631-726c-a364-1e198120694a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2025AcquisitionsMember_019c4748-419f-7590-aec1-16b4a4ed6232" xlink:href="lgn-20251231.xsd#lgn_Total2025AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_Total2025AcquisitionsMember_019c4748-419f-7590-aec1-16b4a4ed6232" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_P2SLPMember_019b7ce4-0b1a-7ba9-a009-14a8315f62ed" xlink:href="lgn-20251231.xsd#lgn_P2SLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_P2SLPMember_019b7ce4-0b1a-7ba9-a009-14a8315f62ed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b7ce4-0b1a-7248-8757-eff8f3f5a42f" xlink:href="lgn-20251231.xsd#lgn_AMAConsultingEngineersHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b7ce4-0b1a-7248-8757-eff8f3f5a42f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2024AcquisitionMember_019b7ce4-0b1a-7922-ba66-e86eeed6debe" xlink:href="lgn-20251231.xsd#lgn_Other2024AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_Other2024AcquisitionMember_019b7ce4-0b1a-7922-ba66-e86eeed6debe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2024AcquisitionsMember_019b9881-800f-7cd6-b287-570a26e9994e" xlink:href="lgn-20251231.xsd#lgn_Total2024AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b7ce4-0b1a-7d82-9d88-55634eb448c1" xlink:to="loc_lgn_Total2024AcquisitionsMember_019b9881-800f-7cd6-b287-570a26e9994e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cb8f8-4df3-7470-b884-5d7933b8c14b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-75e9-ac5d-a2c91778acaa" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cb8f8-4df3-7470-b884-5d7933b8c14b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8f8-4df3-7470-b884-5d7933b8c14b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8f8-4df3-7470-b884-5d7933b8c14b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8f8-4df3-7470-b884-5d7933b8c14b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8f8-4df3-75bb-a9e8-691a2d156a23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8f8-4df3-7470-b884-5d7933b8c14b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8f8-4df3-75bb-a9e8-691a2d156a23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cb8f8-4df3-76bd-ab0d-95f57d5a6220" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cb8f8-4df3-75bb-a9e8-691a2d156a23" xlink:to="loc_us-gaap_SubsequentEventMember_019cb8f8-4df3-76bd-ab0d-95f57d5a6220" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cf738-775b-74c0-87c2-a9c189a40e78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b7ce4-0b1a-75e9-ac5d-a2c91778acaa" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cf738-775b-74c0-87c2-a9c189a40e78" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cf738-775b-74c0-87c2-a9c189a40e78_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cf738-775b-74c0-87c2-a9c189a40e78" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cf738-775b-74c0-87c2-a9c189a40e78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cf738-775b-76fc-86a1-688019701d20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cf738-775b-74c0-87c2-a9c189a40e78" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cf738-775b-76fc-86a1-688019701d20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019cf738-775b-74bd-bf26-4f684d5990ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cf738-775b-76fc-86a1-688019701d20" xlink:to="loc_us-gaap_TradeNamesMember_019cf738-775b-74bd-bf26-4f684d5990ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7ddf-a7bb-707aab054353" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019b7ce4-0b1a-743b-80ba-c16b50651b60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019b7ce4-0b1a-743b-80ba-c16b50651b60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019b7ce4-0b1a-748e-8dd0-d09d075455d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019b7ce4-0b1a-748e-8dd0-d09d075455d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedAssetAcquiredContractAssets_019b7ce4-0b1a-7b2d-a8d9-f459b57f24e0" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedAssetAcquiredContractAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedAssetAcquiredContractAssets_019b7ce4-0b1a-7b2d-a8d9-f459b57f24e0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_019b7ce4-0b1a-78f8-a1dc-bc1455c2cc27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_019b7ce4-0b1a-78f8-a1dc-bc1455c2cc27" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019b7ce4-0b1a-7062-a07f-cdf4fc82e8e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019b7ce4-0b1a-7062-a07f-cdf4fc82e8e3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedAssetAcquiredAssetOperatingLeaseRightOfUseAssets_019b7ce4-0b1a-783e-8245-16f107cdfeea" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedAssetAcquiredAssetOperatingLeaseRightOfUseAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedAssetAcquiredAssetOperatingLeaseRightOfUseAssets_019b7ce4-0b1a-783e-8245-16f107cdfeea" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019b7ce4-0b1a-7bbe-9ace-2b3bd80299d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_Goodwill_019b7ce4-0b1a-7bbe-9ace-2b3bd80299d4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019b7ce4-0b1a-7bd9-9f4c-fb316d05b47a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019b7ce4-0b1a-7bd9-9f4c-fb316d05b47a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019b7ce4-0b1a-7a6c-9a1f-3d3b2f365fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019b7ce4-0b1a-7a6c-9a1f-3d3b2f365fcc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAcquiredIncludingGoodwill_019b7ce4-0b1a-7fd1-bf5b-348ae6bea78d" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAcquiredIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAcquiredIncludingGoodwill_019b7ce4-0b1a-7fd1-bf5b-348ae6bea78d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019b7ce4-0b1a-724a-a55d-f009c079aadc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019b7ce4-0b1a-724a-a55d-f009c079aadc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedCompensationAndBenefits_019b7ce4-0b1a-798b-a995-1d2985e548c4" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedCompensationAndBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedCompensationAndBenefits_019b7ce4-0b1a-798b-a995-1d2985e548c4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedAndOtherLiabilitiesCurrent_019b7ce4-0b1a-7d26-b314-b0d3c83ad53e" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedAndOtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedLiabilityAccruedAndOtherLiabilitiesCurrent_019b7ce4-0b1a-7d26-b314-b0d3c83ad53e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedContractLiability_019b7ce4-0b1a-7835-93da-68f662f5dba2" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedLiabilityAssumedContractLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedContractLiability_019b7ce4-0b1a-7835-93da-68f662f5dba2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesCurrent_019b7ce4-0b1a-7206-b4ae-cb5a1309ae53" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesCurrent_019b7ce4-0b1a-7206-b4ae-cb5a1309ae53" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_019b7ce4-0b1a-7867-90be-9229c8750743" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_019b7ce4-0b1a-7867-90be-9229c8750743" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesNoncurrent_019b7ce4-0b1a-7c8c-8fa9-ccb27d332cbf" xlink:href="lgn-20251231.xsd#lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_lgn_BusinessCombinationRecognizedLiabilityAssumedOperatingLeaseLiabilitiesNoncurrent_019b7ce4-0b1a-7c8c-8fa9-ccb27d332cbf" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_019b7ce4-0b1a-785c-b464-baf2f805b911" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_019b7ce4-0b1a-785c-b464-baf2f805b911" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019b7ce4-0b1a-781a-97f7-0ecbd83fafef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019b7ce4-0b1a-781a-97f7-0ecbd83fafef" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019b7ce4-0b1a-7946-afda-38da5ff220ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019b7ce4-0b1a-7946-afda-38da5ff220ca" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019b7ce4-0b1a-7644-99d0-04b332d379af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_019b7ce4-0b1a-77bd-b67e-7d83a997a337" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019b7ce4-0b1a-7644-99d0-04b332d379af" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019b7ce4-0b1a-7ba0-8ed0-5ecbacf65537" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b7ce4-0b1a-7ddf-a7bb-707aab054353" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019b7ce4-0b1a-7ba0-8ed0-5ecbacf65537" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/AcquisitionsScheduleofIdentifiableIntangibleAssetsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#AcquisitionsScheduleofIdentifiableIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/AcquisitionsScheduleofIdentifiableIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019b8c25-b619-76b0-b0f2-10c8d2b112ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b8c25-b619-79d9-82cc-f7a71c8589f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b8c25-b619-76b0-b0f2-10c8d2b112ff" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b8c25-b619-79d9-82cc-f7a71c8589f3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019b8c25-b619-75de-b2e0-c8ffc1a44053" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b8c25-b619-79d9-82cc-f7a71c8589f3" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019b8c25-b619-75de-b2e0-c8ffc1a44053" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-75de-b2e0-c8ffc1a44053_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b8c25-b619-75de-b2e0-c8ffc1a44053" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-75de-b2e0-c8ffc1a44053_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b8c25-b619-75de-b2e0-c8ffc1a44053" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IMDMember_019c474e-9a26-7b0a-9ca3-9f4f656f9ad4" xlink:href="lgn-20251231.xsd#lgn_IMDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_IMDMember_019c474e-9a26-7b0a-9ca3-9f4f656f9ad4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2025AcquisitionMember_019c99d6-69b2-7bc4-902d-c29f0c542067" xlink:href="lgn-20251231.xsd#lgn_Other2025AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_Other2025AcquisitionMember_019c99d6-69b2-7bc4-902d-c29f0c542067" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2025AcquisitionsMember_019c474e-b82c-7e7e-a0a9-da03ea41b1aa" xlink:href="lgn-20251231.xsd#lgn_Total2025AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_Total2025AcquisitionsMember_019c474e-b82c-7e7e-a0a9-da03ea41b1aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_P2SLPMember_019b8c25-b619-79b0-9f6a-aed505f81eb2" xlink:href="lgn-20251231.xsd#lgn_P2SLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_P2SLPMember_019b8c25-b619-79b0-9f6a-aed505f81eb2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b8c26-7fe7-7489-bfa6-c56bd1b19250" xlink:href="lgn-20251231.xsd#lgn_AMAConsultingEngineersHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_AMAConsultingEngineersHoldingsLLCMember_019b8c26-7fe7-7489-bfa6-c56bd1b19250" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2024AcquisitionMember_019b8c26-f960-719e-9747-2ca2e1d92933" xlink:href="lgn-20251231.xsd#lgn_Other2024AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_Other2024AcquisitionMember_019b8c26-f960-719e-9747-2ca2e1d92933" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Total2024AcquisitionsMember_019b9888-adf7-7c76-a58b-ff1561cbb92c" xlink:href="lgn-20251231.xsd#lgn_Total2024AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c25-b619-711a-897f-e88a37f3f2cf" xlink:to="loc_lgn_Total2024AcquisitionsMember_019b9888-adf7-7c76-a58b-ff1561cbb92c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b8c33-6d56-71a2-a57f-e193c4805efd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b8c25-b619-79d9-82cc-f7a71c8589f3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b8c33-6d56-71a2-a57f-e193c4805efd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-71a2-a57f-e193c4805efd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b8c33-6d56-71a2-a57f-e193c4805efd" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-71a2-a57f-e193c4805efd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-7833-8c74-176e2a11934e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b8c33-6d56-71a2-a57f-e193c4805efd" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-7833-8c74-176e2a11934e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelatedIntangibleAssetsMember_019b8c33-6d56-7145-a6e7-e00260ee69d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelatedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-7833-8c74-176e2a11934e" xlink:to="loc_us-gaap_CustomerRelatedIntangibleAssetsMember_019b8c33-6d56-7145-a6e7-e00260ee69d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019cf791-dcd9-7465-850e-a921658479df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-7833-8c74-176e2a11934e" xlink:to="loc_us-gaap_TradeNamesMember_019cf791-dcd9-7465-850e-a921658479df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_019b8c59-b861-7e1c-930d-5fe19e6357cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b8c33-6d56-7833-8c74-176e2a11934e" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_019b8c59-b861-7e1c-930d-5fe19e6357cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cb8fa-fa33-7570-8202-55249a46604c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019b8c25-b619-79d9-82cc-f7a71c8589f3" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cb8fa-fa33-7570-8202-55249a46604c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8fa-fa33-7570-8202-55249a46604c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8fa-fa33-7570-8202-55249a46604c" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8fa-fa33-7570-8202-55249a46604c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cb8fb-5aef-7444-9b0f-1102c5a17c77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cb8fa-fa33-7570-8202-55249a46604c" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cb8fb-5aef-7444-9b0f-1102c5a17c77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cb8fb-7df1-7171-88a9-ba59362266a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cb8fb-5aef-7444-9b0f-1102c5a17c77" xlink:to="loc_us-gaap_SubsequentEventMember_019cb8fb-7df1-7171-88a9-ba59362266a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019be5f9-f1d4-7328-97e7-acf7d8cab2bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b8c25-b619-76b0-b0f2-10c8d2b112ff" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019be5f9-f1d4-7328-97e7-acf7d8cab2bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019b8c69-a80a-74f0-b75f-dc0d80516a89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019b8c25-b619-76b0-b0f2-10c8d2b112ff" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019b8c69-a80a-74f0-b75f-dc0d80516a89" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsScheduleofChangesintheCarryingValueofGoodwillbySegmentDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#GoodwillandIntangibleAssetsScheduleofChangesintheCarryingValueofGoodwillbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsScheduleofChangesintheCarryingValueofGoodwillbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7569-a46b-35addfda86b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7978-b5c8-83cc33451118" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7569-a46b-35addfda86b3" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7978-b5c8-83cc33451118" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019b44c5-88d1-7c0e-b013-cc839fbdfcd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7978-b5c8-83cc33451118" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019b44c5-88d1-7c0e-b013-cc839fbdfcd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b44c5-88d1-7c0e-b013-cc839fbdfcd3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b44c5-88d1-7c0e-b013-cc839fbdfcd3" xlink:to="loc_us-gaap_SegmentDomain_019b44c5-88d1-7c0e-b013-cc839fbdfcd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b44c5-88d1-7bf1-8324-b23666ada6ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b44c5-88d1-7c0e-b013-cc839fbdfcd3" xlink:to="loc_us-gaap_SegmentDomain_019b44c5-88d1-7bf1-8324-b23666ada6ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringAndConsultingMember_019b44c5-88d1-765d-a0d5-8ab2d018185b" xlink:href="lgn-20251231.xsd#lgn_EngineeringAndConsultingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b44c5-88d1-7bf1-8324-b23666ada6ba" xlink:to="loc_lgn_EngineeringAndConsultingMember_019b44c5-88d1-765d-a0d5-8ab2d018185b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InstallationAndMaintenanceMember_019b44c5-88d1-7987-ae37-ad691a1739d3" xlink:href="lgn-20251231.xsd#lgn_InstallationAndMaintenanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b44c5-88d1-7bf1-8324-b23666ada6ba" xlink:to="loc_lgn_InstallationAndMaintenanceMember_019b44c5-88d1-7987-ae37-ad691a1739d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7569-a46b-35addfda86b3" xlink:to="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019b44c5-88d1-785e-ad67-0c35c7064948" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:to="loc_us-gaap_Goodwill_019b44c5-88d1-785e-ad67-0c35c7064948" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019b44cb-6d78-7ff4-9d29-d5a46ab32730" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019b44cb-6d78-7ff4-9d29-d5a46ab32730" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019b44c5-88d1-7df3-ace5-104698abd58a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019b44c5-88d1-7df3-ace5-104698abd58a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019b44c5-88d1-719d-86c8-ce2ec92bc2f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019b44c5-88d1-7e16-8fb9-4967916d0954" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019b44c5-88d1-719d-86c8-ce2ec92bc2f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019b44c5-88d1-753f-9a19-edb7325e32dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLossAbstract_019b44d0-610a-73e7-afdc-eefa699382dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7569-a46b-35addfda86b3" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLossAbstract_019b44d0-610a-73e7-afdc-eefa699382dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019b44cf-6d14-77cd-8583-c288d7f301c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLossAbstract_019b44d0-610a-73e7-afdc-eefa699382dc" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019b44cf-6d14-77cd-8583-c288d7f301c7" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#GoodwillandIntangibleAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7b52-98ef-6491d270f731" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-769b-93b9-0f42cd359f75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7b52-98ef-6491d270f731" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-769b-93b9-0f42cd359f75" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019b44da-6d90-7d1f-bf28-607c7dccd514" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-769b-93b9-0f42cd359f75" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019b44da-6d90-7d1f-bf28-607c7dccd514" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b44da-6d90-7d1f-bf28-607c7dccd514_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b44da-6d90-7d1f-bf28-607c7dccd514" xlink:to="loc_us-gaap_SegmentDomain_019b44da-6d90-7d1f-bf28-607c7dccd514_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b44da-6d90-7155-bb25-4a467eda25aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b44da-6d90-7d1f-bf28-607c7dccd514" xlink:to="loc_us-gaap_SegmentDomain_019b44da-6d90-7155-bb25-4a467eda25aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringAndConsultingMember_019b44da-a0f8-7d39-b595-27a85f72e485" xlink:href="lgn-20251231.xsd#lgn_EngineeringAndConsultingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b44da-6d90-7155-bb25-4a467eda25aa" xlink:to="loc_lgn_EngineeringAndConsultingMember_019b44da-a0f8-7d39-b595-27a85f72e485" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InstallationAndMaintenanceMember_019b44da-6d90-7b61-a1bf-121e8b1361a8" xlink:href="lgn-20251231.xsd#lgn_InstallationAndMaintenanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b44da-6d90-7155-bb25-4a467eda25aa" xlink:to="loc_lgn_InstallationAndMaintenanceMember_019b44da-6d90-7b61-a1bf-121e8b1361a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019b44d7-442a-7615-af6a-752379774a28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7b52-98ef-6491d270f731" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019b44d7-442a-7615-af6a-752379774a28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019b9bf6-ed7e-7663-9e74-e063ed0ba051" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-7b52-98ef-6491d270f731" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019b9bf6-ed7e-7663-9e74-e063ed0ba051" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#GoodwillandIntangibleAssetsScheduleofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/GoodwillandIntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7e49-ab03-ec8937b2bfd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7e49-ab03-ec8937b2bfd9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b44c5-88d1-748c-971b-c2e2f7f92a82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019b44c5-88d1-7e49-ab03-ec8937b2bfd9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b44c5-88d1-748c-971b-c2e2f7f92a82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-748c-971b-c2e2f7f92a82_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b44c5-88d1-748c-971b-c2e2f7f92a82" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-748c-971b-c2e2f7f92a82_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-7310-83bc-ba08ad597820" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019b44c5-88d1-748c-971b-c2e2f7f92a82" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-7310-83bc-ba08ad597820" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019b44c5-88d1-760b-88a2-49b7c659a240" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-7310-83bc-ba08ad597820" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019b44c5-88d1-760b-88a2-49b7c659a240" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_019b44c5-88d1-77b9-ac0f-a78c88814de0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-7310-83bc-ba08ad597820" xlink:to="loc_us-gaap_TradeNamesMember_019b44c5-88d1-77b9-ac0f-a78c88814de0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_019b44c5-88d1-7b24-b457-bf0175fc2c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019b44c5-88d1-7310-83bc-ba08ad597820" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_019b44c5-88d1-7b24-b457-bf0175fc2c7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019b44c5-88d1-7769-828a-cfee42136359" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019b44c5-88d1-7769-828a-cfee42136359" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019b44c5-88d1-7fc5-9ebb-986752e4555a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019b44c5-88d1-7fc5-9ebb-986752e4555a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019b44c5-88d1-725d-975c-cc96dfbad890" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019b44c5-88d1-725d-975c-cc96dfbad890" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019b44c5-88d1-766a-992a-4dc5e97cb154" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019b44c5-88d1-72f5-9fd9-11d7ba0c4105" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019b44c5-88d1-766a-992a-4dc5e97cb154" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/VariableInterestEntitiesandEquityMethodInvestmentsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#VariableInterestEntitiesandEquityMethodInvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/VariableInterestEntitiesandEquityMethodInvestmentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019b44e0-ca8c-7c51-8731-a9c66d7b237b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019b44e0-ca8c-7fe6-bcca-4ccc62e112d7" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019b44e0-ca8c-7c51-8731-a9c66d7b237b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019b44e0-ca8c-77d0-9f7b-b2a2ad9e8a8e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019b44e0-ca8c-7c51-8731-a9c66d7b237b" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019b44e0-ca8c-77d0-9f7b-b2a2ad9e8a8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b44e0-ca8c-78e8-ab18-9ea6d24c261e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b44e0-ca8c-78e8-ab18-9ea6d24c261e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b44e0-ca8c-78e8-ab18-9ea6d24c261e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b44e0-ca8c-78e8-ab18-9ea6d24c261e" xlink:to="loc_us-gaap_RelatedPartyDomain_019b44e0-ca8c-78e8-ab18-9ea6d24c261e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b44e0-ca8c-7120-ac2e-face9a2a64b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b44e0-ca8c-78e8-ab18-9ea6d24c261e" xlink:to="loc_us-gaap_RelatedPartyDomain_019b44e0-ca8c-7120-ac2e-face9a2a64b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_019b44e0-ca8c-770f-b5f8-19438515d952" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvesteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b44e0-ca8c-7120-ac2e-face9a2a64b0" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_019b44e0-ca8c-770f-b5f8-19438515d952" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:to="loc_dei_LegalEntityAxis_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192" xlink:to="loc_dei_EntityDomain_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b44e0-ca8c-76ef-a037-8799dd1c9b05" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019b44e0-ca8c-7d9c-aa77-fb2ed73ee192" xlink:to="loc_dei_EntityDomain_019b44e0-ca8c-76ef-a037-8799dd1c9b05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ProfessionalCorporationsMember_019b44e0-ca8c-7ea1-8cf8-2cb14aaaa8bf" xlink:href="lgn-20251231.xsd#lgn_ProfessionalCorporationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b44e0-ca8c-76ef-a037-8799dd1c9b05" xlink:to="loc_lgn_ProfessionalCorporationsMember_019b44e0-ca8c-7ea1-8cf8-2cb14aaaa8bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b44e0-ca8c-7754-8a85-a3d3bf30bf9c" xlink:to="loc_srt_CounterpartyNameAxis_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019b44e0-ca8c-7d83-8045-d7cd0462e426" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019b44e0-ca8c-7cda-99b5-c8bc3f31b1b2" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019b44e0-ca8c-7d83-8045-d7cd0462e426" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceCorpMember_019b44e0-ca8c-7c8e-bc58-53798fe090e0" xlink:href="lgn-20251231.xsd#lgn_LegenceCorpMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019b44e0-ca8c-7d83-8045-d7cd0462e426" xlink:to="loc_lgn_LegenceCorpMember_019b44e0-ca8c-7c8e-bc58-53798fe090e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NumberOfProfessionalCorporationsContracted_019b44e0-ca8c-7363-8ba0-cda24bf61d13" xlink:href="lgn-20251231.xsd#lgn_NumberOfProfessionalCorporationsContracted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:to="loc_lgn_NumberOfProfessionalCorporationsContracted_019b44e0-ca8c-7363-8ba0-cda24bf61d13" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019b44e0-ca8c-7a13-b538-eee9bd425163" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019b44e0-ca8c-7a13-b538-eee9bd425163" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019b44e0-ca8c-7136-861d-8f9de54a7283" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019b44e0-ca8c-7136-861d-8f9de54a7283" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b44e0-ca8c-7a7d-907c-03013acfb818" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b44e0-ca8c-7762-a824-fa85ed87d3c5" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b44e0-ca8c-7a7d-907c-03013acfb818" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/VariableInterestEntitiesandEquityMethodInvestmentsScheduleofCarryingAmountsandClassificationofthePCsAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#VariableInterestEntitiesandEquityMethodInvestmentsScheduleofCarryingAmountsandClassificationofthePCsAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/VariableInterestEntitiesandEquityMethodInvestmentsScheduleofCarryingAmountsandClassificationofthePCsAssetsandLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019b44e0-ca8c-7f75-a6f6-48b92972171f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019b44e0-ca8c-7f75-a6f6-48b92972171f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019b44e0-ca8c-75a8-a3a0-9193461dc0b8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019b44e0-ca8c-7f75-a6f6-48b92972171f" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019b44e0-ca8c-75a8-a3a0-9193461dc0b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019b44e0-ca8c-75a8-a3a0-9193461dc0b8_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019b44e0-ca8c-75a8-a3a0-9193461dc0b8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019b44e0-ca8c-75a8-a3a0-9193461dc0b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019b44e0-ca8c-7b30-aa7c-7b55c8443006" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019b44e0-ca8c-75a8-a3a0-9193461dc0b8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019b44e0-ca8c-7b30-aa7c-7b55c8443006" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019b44e0-ca8c-7d11-90b1-69a0c33016e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019b44e0-ca8c-7b30-aa7c-7b55c8443006" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019b44e0-ca8c-7d11-90b1-69a0c33016e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Cash_019b44e0-ca8c-7bcb-a3a5-cd9938f44a65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Cash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_Cash_019b44e0-ca8c-7bcb-a3a5-cd9938f44a65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019b44e0-ca8c-74fe-b830-3cd734f63a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019b44e0-ca8c-74fe-b830-3cd734f63a2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019b44e0-ca8c-7244-aaf4-0bafe737061a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019b44e0-ca8c-7244-aaf4-0bafe737061a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019b44e0-ca8c-7ce9-b59e-9834649f6b72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_AssetsCurrent_019b44e0-ca8c-7ce9-b59e-9834649f6b72" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent_019be5d5-192f-7662-b2bd-452faac2b9ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_AssetsNoncurrent_019be5d5-192f-7662-b2bd-452faac2b9ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019b4b3b-8453-71c9-a9a9-45b451f3c20f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_Assets_019b4b3b-8453-71c9-a9a9-45b451f3c20f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019b44e0-ca8c-7c22-8484-68e4a66dbf6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019b44e0-ca8c-7c22-8484-68e4a66dbf6d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_019b44e0-ca8c-7833-b87b-b45245fd21d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_ContractWithCustomerLiability_019b44e0-ca8c-7833-b87b-b45245fd21d3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019b44e0-ca8c-75b6-8120-fbafd2c4c327" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019b44e0-ca8c-7aa8-a04d-3e7c52088fa5" xlink:to="loc_us-gaap_Liabilities_019b44e0-ca8c-75b6-8120-fbafd2c4c327" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/PropertyandEquipmentnetSummaryofPropertyandEquipmentDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#PropertyandEquipmentnetSummaryofPropertyandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/PropertyandEquipmentnetSummaryofPropertyandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b49f8-d942-7568-9947-1d8ef47f8731" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b49f8-d942-7568-9947-1d8ef47f8731" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b49f9-0e43-72c8-83d0-4a188bd189d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019b49f8-d942-7568-9947-1d8ef47f8731" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b49f9-0e43-72c8-83d0-4a188bd189d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-0e43-72c8-83d0-4a188bd189d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b49f9-0e43-72c8-83d0-4a188bd189d7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-0e43-72c8-83d0-4a188bd189d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019b49f9-0e43-72c8-83d0-4a188bd189d7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_019b49fa-62d4-729d-bec6-c6c479967a06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_us-gaap_VehiclesMember_019b49fa-62d4-729d-bec6-c6c479967a06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ComputerEquipmentAndSoftwareMember_019bc2dc-e9e0-70f4-bd44-b0e77f3444e6" xlink:href="lgn-20251231.xsd#lgn_ComputerEquipmentAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_lgn_ComputerEquipmentAndSoftwareMember_019bc2dc-e9e0-70f4-bd44-b0e77f3444e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019b49fb-d19a-7768-a5cf-bca52244f8de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019b49fb-d19a-7768-a5cf-bca52244f8de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_019b49fc-848b-786e-943b-a92e8639408e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_019b49fc-848b-786e-943b-a92e8639408e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019b49fd-5868-762a-bd4f-f3cd38e39e29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019b49fd-5868-762a-bd4f-f3cd38e39e29" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_019b4a00-15e5-7038-be18-4994712c1ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019b49f9-3ecd-7225-a9ec-55586a15c8d8" xlink:to="loc_us-gaap_ConstructionInProgressMember_019b4a00-15e5-7038-be18-4994712c1ea7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019b49f7-3b0e-739c-b8a9-45d439d5782a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019b49f7-3b0e-739c-b8a9-45d439d5782a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019bc2dd-365c-7c53-87bd-fb09cf06d7f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019bc2dd-365c-7c53-87bd-fb09cf06d7f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_019bc2dd-e4f4-752d-8a08-b4e6f4bc3e3c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_019bc2dd-e4f4-752d-8a08-b4e6f4bc3e3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_019b49f7-7a3a-703a-9ccd-d9b2f29db448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_019b49f7-7a3a-703a-9ccd-d9b2f29db448" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019b49f7-9f18-7869-824c-04bef9623b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019b49f9-86ea-75a1-b3e7-12ff41c6fb80" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019b49f7-9f18-7869-824c-04bef9623b6f" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/LeasesScheduleofSupplementalBalanceSheetInformationRelatedtoOperatingandFinanceLeasesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#LeasesScheduleofSupplementalBalanceSheetInformationRelatedtoOperatingandFinanceLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/LeasesScheduleofSupplementalBalanceSheetInformationRelatedtoOperatingandFinanceLeasesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4aa9-900d-70c4-bec8-51a944021b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_019b4aa7-40b4-7d37-9526-0f915fda180a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4aa9-900d-70c4-bec8-51a944021b7a" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019b4aa7-40b4-7d37-9526-0f915fda180a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4aa8-f197-7334-b7e7-b7006845f352" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019b4aa7-40b4-7d37-9526-0f915fda180a" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4aa8-f197-7334-b7e7-b7006845f352" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4aa8-f197-7334-b7e7-b7006845f352_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4aa8-f197-7334-b7e7-b7006845f352" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4aa8-f197-7334-b7e7-b7006845f352_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4aa9-3a04-7df3-94c1-d802cfe3b0d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4aa8-f197-7334-b7e7-b7006845f352" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4aa9-3a04-7df3-94c1-d802cfe3b0d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019b4aa9-e89e-7f82-9072-be3743059fae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4aa9-3a04-7df3-94c1-d802cfe3b0d3" xlink:to="loc_us-gaap_RelatedPartyMember_019b4aa9-e89e-7f82-9072-be3743059fae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019bc2e3-103f-7d7d-a27d-85fc8b89a2a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4aa9-3a04-7df3-94c1-d802cfe3b0d3" xlink:to="loc_us-gaap_NonrelatedPartyMember_019bc2e3-103f-7d7d-a27d-85fc8b89a2a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:href="lgn-20251231.xsd#lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4aa9-900d-70c4-bec8-51a944021b7a" xlink:to="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset_019b4a9b-ab50-7806-ad27-ef57a51d1df3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAsset_019b4a9b-ab50-7806-ad27-ef57a51d1df3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_019d2550-c58c-72f6-9730-bb71677c7082" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_019d2550-c58c-72f6-9730-bb71677c7082" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrent_019b4a9b-ab50-73b0-a0f9-6df4e5358f0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseLiabilityCurrent_019b4a9b-ab50-73b0-a0f9-6df4e5358f0a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList_019d2551-1ef1-746e-b537-fac851e5cd13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList_019d2551-1ef1-746e-b537-fac851e5cd13" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_019b4a9b-ab50-7680-bd2c-8c4cb6c78626" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_019b4a9b-ab50-7680-bd2c-8c4cb6c78626" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_019b4a9b-ab50-734c-9b07-93690ca2530c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019b4a9b-717e-7148-9bc0-d12aafee9754" xlink:to="loc_us-gaap_FinanceLeaseLiability_019b4a9b-ab50-734c-9b07-93690ca2530c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_WeightedAverageRemainingLeaseTermAbstract_019b4a9c-2d2c-7f7a-90fc-ac6f5e85dbb8" xlink:href="lgn-20251231.xsd#lgn_WeightedAverageRemainingLeaseTermAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4aa9-900d-70c4-bec8-51a944021b7a" xlink:to="loc_lgn_WeightedAverageRemainingLeaseTermAbstract_019b4a9c-2d2c-7f7a-90fc-ac6f5e85dbb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_019b4a9c-fca5-72b9-af28-f00e6e0cc11b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_WeightedAverageRemainingLeaseTermAbstract_019b4a9c-2d2c-7f7a-90fc-ac6f5e85dbb8" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_019b4a9c-fca5-72b9-af28-f00e6e0cc11b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_019b4a9c-fca5-7ab6-b62f-930f4adb3e20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_WeightedAverageRemainingLeaseTermAbstract_019b4a9c-2d2c-7f7a-90fc-ac6f5e85dbb8" xlink:to="loc_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_019b4a9c-fca5-7ab6-b62f-930f4adb3e20" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LeasesWeightedAverageDiscountRateAbstract_019b4a9c-84e8-7335-a7db-c58b845f04b7" xlink:href="lgn-20251231.xsd#lgn_LeasesWeightedAverageDiscountRateAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4aa9-900d-70c4-bec8-51a944021b7a" xlink:to="loc_lgn_LeasesWeightedAverageDiscountRateAbstract_019b4a9c-84e8-7335-a7db-c58b845f04b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_019b4a9e-25e0-733a-b727-a588967e4be1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_LeasesWeightedAverageDiscountRateAbstract_019b4a9c-84e8-7335-a7db-c58b845f04b7" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_019b4a9e-25e0-733a-b727-a588967e4be1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_019b4a9e-25e0-70cf-9619-b830d5981611" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_LeasesWeightedAverageDiscountRateAbstract_019b4a9c-84e8-7335-a7db-c58b845f04b7" xlink:to="loc_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_019b4a9e-25e0-70cf-9619-b830d5981611" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/LeasesComponentsofLeaseExpenseDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#LeasesComponentsofLeaseExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/LeasesComponentsofLeaseExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_019b4ae1-a09c-7a5a-a018-57252e8a06a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019b4ae1-a09c-7a5a-a018-57252e8a06a8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019b4ae1-a09c-7a5a-a018-57252e8a06a8" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4b05-23a2-7b90-8c43-25e74b7101c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b04-f0c2-7e77-a08b-cd416ecfb3ca" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4b05-23a2-7b90-8c43-25e74b7101c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019b4b05-6737-7c53-af2b-59ff66d8deee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4b05-23a2-7b90-8c43-25e74b7101c2" xlink:to="loc_us-gaap_RelatedPartyMember_019b4b05-6737-7c53-af2b-59ff66d8deee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019bc2e5-4fa9-782b-8920-e5ca29fa4bb7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4b05-23a2-7b90-8c43-25e74b7101c2" xlink:to="loc_us-gaap_NonrelatedPartyMember_019bc2e5-4fa9-782b-8920-e5ca29fa4bb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019b4ae2-69f7-71fd-abc3-0cd15f98f50f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019b4ae1-a09c-7a5a-a018-57252e8a06a8" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019b4ae2-69f7-71fd-abc3-0cd15f98f50f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-69f7-71fd-abc3-0cd15f98f50f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019b4ae2-69f7-71fd-abc3-0cd15f98f50f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-69f7-71fd-abc3-0cd15f98f50f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-9066-78c8-bb6a-12a0682084ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019b4ae2-69f7-71fd-abc3-0cd15f98f50f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-9066-78c8-bb6a-12a0682084ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019be5c8-2870-7290-b7f4-24926ebb3ee7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-9066-78c8-bb6a-12a0682084ce" xlink:to="loc_us-gaap_CostOfSalesMember_019be5c8-2870-7290-b7f4-24926ebb3ee7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_019b4ae3-4a14-7bbe-bf5a-25f65a554068" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019b4ae2-9066-78c8-bb6a-12a0682084ce" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_019b4ae3-4a14-7bbe-bf5a-25f65a554068" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_FinanceLeaseExpenseAbstract_019b4ac8-a7fd-781f-a163-6d29642f3c20" xlink:href="lgn-20251231.xsd#lgn_FinanceLeaseExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_lgn_FinanceLeaseExpenseAbstract_019b4ac8-a7fd-781f-a163-6d29642f3c20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_019b4ac9-11ce-7b70-b908-28c0a6ba83fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseExpenseAbstract_019b4ac8-a7fd-781f-a163-6d29642f3c20" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_019b4ac9-11ce-7b70-b908-28c0a6ba83fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestExpense_019b4ac9-5488-7693-baf4-b27166c7db95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_FinanceLeaseExpenseAbstract_019b4ac8-a7fd-781f-a163-6d29642f3c20" xlink:to="loc_us-gaap_FinanceLeaseInterestExpense_019b4ac9-5488-7693-baf4-b27166c7db95" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_019b4acd-3815-7516-81c1-79b3d2dce9b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_us-gaap_OperatingLeaseCost_019b4acd-3815-7516-81c1-79b3d2dce9b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermLeaseCost_019b4acc-5215-77bb-9c49-0df966156455" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermLeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_us-gaap_ShortTermLeaseCost_019b4acc-5215-77bb-9c49-0df966156455" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost_019b4acc-93cc-7a41-aa77-cd35586f440f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_us-gaap_VariableLeaseCost_019b4acc-93cc-7a41-aa77-cd35586f440f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_019b4acc-df0e-73c9-93af-1b9b4f92d880" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4ae1-e6e7-7c8f-b883-eff87eb84b22" xlink:to="loc_us-gaap_LeaseCost_019b4acc-df0e-73c9-93af-1b9b4f92d880" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/LeasesSupplementalCashFlowandOtherInformationRelatedtoOperatingandFinanceLeasesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#LeasesSupplementalCashFlowandOtherInformationRelatedtoOperatingandFinanceLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/LeasesSupplementalCashFlowandOtherInformationRelatedtoOperatingandFinanceLeasesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4b1c-d554-7ac7-b083-2b2ec6728e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_019b4b14-b9c9-7a52-b1e1-e5bf6ca3624e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4b1c-d554-7ac7-b083-2b2ec6728e9a" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019b4b14-b9c9-7a52-b1e1-e5bf6ca3624e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b14-b9c9-740b-9f9b-423e52268642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019b4b14-b9c9-7a52-b1e1-e5bf6ca3624e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b14-b9c9-740b-9f9b-423e52268642" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-740b-9f9b-423e52268642_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b14-b9c9-740b-9f9b-423e52268642" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-740b-9f9b-423e52268642_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-757e-ad39-e50d9b7ac7d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019b4b14-b9c9-740b-9f9b-423e52268642" xlink:to="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-757e-ad39-e50d9b7ac7d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019b4b14-b9c9-784b-907a-7d141e82865d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-757e-ad39-e50d9b7ac7d6" xlink:to="loc_us-gaap_RelatedPartyMember_019b4b14-b9c9-784b-907a-7d141e82865d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019bc2e5-6fd4-7be2-9c0f-c1d7b4392f30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019b4b14-b9c9-757e-ad39-e50d9b7ac7d6" xlink:to="loc_us-gaap_NonrelatedPartyMember_019bc2e5-6fd4-7be2-9c0f-c1d7b4392f30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract_019b4b2b-aa2e-7182-9c6e-4d4020b3cd73" xlink:href="lgn-20251231.xsd#lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4b1c-d554-7ac7-b083-2b2ec6728e9a" xlink:to="loc_lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract_019b4b2b-aa2e-7182-9c6e-4d4020b3cd73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasePayments_019b4b1c-d554-7b34-9a4e-1f69c06a2e10" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeasePayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract_019b4b2b-aa2e-7182-9c6e-4d4020b3cd73" xlink:to="loc_us-gaap_OperatingLeasePayments_019b4b1c-d554-7b34-9a4e-1f69c06a2e10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability_019b4b1c-d554-7dfe-8731-fdfeca72ecaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestPaymentOnLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract_019b4b2b-aa2e-7182-9c6e-4d4020b3cd73" xlink:to="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability_019b4b1c-d554-7dfe-8731-fdfeca72ecaa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_019b4b1c-d554-7f09-87d9-09da887c4c1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_CashPaidForAmountsIncludedInTheMeasurementOfLeaseLiabilitiesAbstract_019b4b2b-aa2e-7182-9c6e-4d4020b3cd73" xlink:to="loc_us-gaap_FinanceLeasePrincipalPayments_019b4b1c-d554-7f09-87d9-09da887c4c1e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SupplementalNoncashInformationAbstract_019b4b2c-2531-7e40-86dc-a92d903250c3" xlink:href="lgn-20251231.xsd#lgn_SupplementalNoncashInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019b4b1c-d554-7ac7-b083-2b2ec6728e9a" xlink:to="loc_lgn_SupplementalNoncashInformationAbstract_019b4b2c-2531-7e40-86dc-a92d903250c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019b4b2d-1df9-7bb9-a2e0-08b63169ea37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_SupplementalNoncashInformationAbstract_019b4b2c-2531-7e40-86dc-a92d903250c3" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019b4b2d-1df9-7bb9-a2e0-08b63169ea37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_019b4b2d-4621-730b-bf79-7f395b4ad738" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_SupplementalNoncashInformationAbstract_019b4b2c-2531-7e40-86dc-a92d903250c3" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_019b4b2d-4621-730b-bf79-7f395b4ad738" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RightOfUseAssetModificationsForOperatingLeases_019b4b2e-bfda-7f79-82bf-e21c87542fc2" xlink:href="lgn-20251231.xsd#lgn_RightOfUseAssetModificationsForOperatingLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_SupplementalNoncashInformationAbstract_019b4b2c-2531-7e40-86dc-a92d903250c3" xlink:to="loc_lgn_RightOfUseAssetModificationsForOperatingLeases_019b4b2e-bfda-7f79-82bf-e21c87542fc2" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DebtScheduleofDebtObligationsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DebtScheduleofDebtObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DebtScheduleofDebtObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-77fa-8031-f7c541a871f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-77fa-8031-f7c541a871f1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-77fa-8031-f7c541a871f1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-757e-9851-7710e1d95169" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019b6cec-7d92-7bf2-a3d6-cb5c8213c0e8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-757e-9851-7710e1d95169" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019b6cec-7d92-7d3d-96d7-76a4ac75f69f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-757e-9851-7710e1d95169" xlink:to="loc_us-gaap_SecuredDebtMember_019b6cec-7d92-7d3d-96d7-76a4ac75f69f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019b6cec-7d92-7c2b-8b34-3d05808b6d88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019b6cec-7d92-757e-9851-7710e1d95169" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019b6cec-7d92-7c2b-8b34-3d05808b6d88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019b6cec-7d92-71c2-a04e-90a213f755cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019b6cec-7d92-71c2-a04e-90a213f755cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_019bc2ee-4138-74ef-b1d4-b30229210e0b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_FinanceLeaseLiability_019bc2ee-4138-74ef-b1d4-b30229210e0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities_019b6cec-7d92-763c-919f-5ddd7e28539f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities_019b6cec-7d92-763c-919f-5ddd7e28539f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019b6cec-7d92-7088-9213-062011d7cf12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019b6cec-7d92-7088-9213-062011d7cf12" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019b6cec-7d92-70cf-8cc4-890cded9eb94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019b6cec-7d92-70cf-8cc4-890cded9eb94" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019b6cec-7d92-758d-9c79-b226c821841d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d92-7afd-a751-d00cb0ac8312" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019b6cec-7d92-758d-9c79-b226c821841d" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DebtTermLoanDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DebtTermLoanDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DebtTermLoanDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d1aef-4c53-745e-8911-2b2940702e30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d1aef-4c53-745e-8911-2b2940702e30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-745e-8911-2b2940702e30_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d1aef-4c53-745e-8911-2b2940702e30" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-745e-8911-2b2940702e30_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-71fa-b7cf-904d5c156e69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019d1aef-4c53-745e-8911-2b2940702e30" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-71fa-b7cf-904d5c156e69" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d1aef-4c53-7540-9021-d13bd94a1cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-71fa-b7cf-904d5c156e69" xlink:to="loc_us-gaap_SecuredDebtMember_019d1aef-4c53-7540-9021-d13bd94a1cf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019d3f48-17ed-71e5-9d87-0871f0a9aaec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d1aef-4c53-71fa-b7cf-904d5c156e69" xlink:to="loc_us-gaap_LineOfCreditMember_019d3f48-17ed-71e5-9d87-0871f0a9aaec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_us-gaap_CreditFacilityAxis_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0" xlink:to="loc_us-gaap_CreditFacilityDomain_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d3f48-7f23-7646-8973-b6a9ba575b1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019d3f48-7f23-7fc3-8cf6-5ee4dbc181e0" xlink:to="loc_us-gaap_CreditFacilityDomain_019d3f48-7f23-7646-8973-b6a9ba575b1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019d3f48-9c07-7a92-bccc-09c1d869947b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019d3f48-7f23-7646-8973-b6a9ba575b1f" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019d3f48-9c07-7a92-bccc-09c1d869947b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019d1aef-4c53-70bc-b59f-156104ba52f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_us-gaap_VariableRateAxis_019d1aef-4c53-70bc-b59f-156104ba52f7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d1aef-4c53-70bc-b59f-156104ba52f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019d1aef-4c53-70bc-b59f-156104ba52f7" xlink:to="loc_us-gaap_VariableRateDomain_019d1aef-4c53-70bc-b59f-156104ba52f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d1aef-4c53-7a39-a48d-c5a1786f2f58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019d1aef-4c53-70bc-b59f-156104ba52f7" xlink:to="loc_us-gaap_VariableRateDomain_019d1aef-4c53-7a39-a48d-c5a1786f2f58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019d1aef-4c53-7077-9937-da1508da4ccb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d1aef-4c53-7a39-a48d-c5a1786f2f58" xlink:to="loc_us-gaap_BaseRateMember_019d1aef-4c53-7077-9937-da1508da4ccb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d1aef-b4c2-7a87-9484-fdb6ba1d1a80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d1aef-4c53-7a39-a48d-c5a1786f2f58" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d1aef-b4c2-7a87-9484-fdb6ba1d1a80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019d1aef-b4c2-71f1-b305-c6f2370c2f82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalFundsEffectiveSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d1aef-4c53-7a39-a48d-c5a1786f2f58" xlink:to="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019d1aef-b4c2-71f1-b305-c6f2370c2f82" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d1aef-4c53-70a3-b38d-bf5fb5098e74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d1aef-4c53-70a3-b38d-bf5fb5098e74" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d1aef-4c53-70a3-b38d-bf5fb5098e74_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d1aef-4c53-70a3-b38d-bf5fb5098e74" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d1aef-4c53-70a3-b38d-bf5fb5098e74_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d1aef-4c53-77a3-8645-586ab5e418f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019d1aef-4c53-70a3-b38d-bf5fb5098e74" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d1aef-4c53-77a3-8645-586ab5e418f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IncrementalTermLoanMember_019d1aef-4c53-77e0-bafd-da401e9db720" xlink:href="lgn-20251231.xsd#lgn_IncrementalTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d1aef-4c53-77a3-8645-586ab5e418f3" xlink:to="loc_lgn_IncrementalTermLoanMember_019d1aef-4c53-77e0-bafd-da401e9db720" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019d1aef-b4c2-76c4-a0d6-5992ab78995d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_srt_RangeAxis_019d1aef-b4c2-76c4-a0d6-5992ab78995d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d1aef-b4c2-76c4-a0d6-5992ab78995d_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019d1aef-b4c2-76c4-a0d6-5992ab78995d" xlink:to="loc_srt_RangeMember_019d1aef-b4c2-76c4-a0d6-5992ab78995d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019d1aef-b4c2-7f1a-97c2-10ad2cbcba2e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019d1aef-b4c2-76c4-a0d6-5992ab78995d" xlink:to="loc_srt_RangeMember_019d1aef-b4c2-7f1a-97c2-10ad2cbcba2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019d1aef-b4c2-7fa8-bcbb-634b345db9f0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d1aef-b4c2-7f1a-97c2-10ad2cbcba2e" xlink:to="loc_srt_MinimumMember_019d1aef-b4c2-7fa8-bcbb-634b345db9f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019d1aef-b4c2-78bc-a1cc-f09500b08deb" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019d1aef-b4c2-7f1a-97c2-10ad2cbcba2e" xlink:to="loc_srt_MaximumMember_019d1aef-b4c2-78bc-a1cc-f09500b08deb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019d1aef-b4c2-73de-aa4a-ec23b55df75b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d92-72b1-afa4-e873df1c3c4f" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019d1aef-b4c2-73de-aa4a-ec23b55df75b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019d1aef-b4c2-73de-aa4a-ec23b55df75b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019d1aef-b4c2-73de-aa4a-ec23b55df75b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019d1aef-b4c2-73de-aa4a-ec23b55df75b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019d1aef-b4c2-79c3-a8bf-118f5f098ad6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019d1aef-b4c2-73de-aa4a-ec23b55df75b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019d1aef-b4c2-79c3-a8bf-118f5f098ad6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019d1aef-b4c2-735e-b024-ec9ffa20aaa9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019d1aef-b4c2-79c3-a8bf-118f5f098ad6" xlink:to="loc_us-gaap_SubsequentEventMember_019d1aef-b4c2-735e-b024-ec9ffa20aaa9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d3f47-406d-7826-9c74-eb7666e7285f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d3f47-406d-7826-9c74-eb7666e7285f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DebtInstrumentAdditionalSpreadAdjustmentOnVariableRate_019d1aef-4c53-739b-8ced-f33415468923" xlink:href="lgn-20251231.xsd#lgn_DebtInstrumentAdditionalSpreadAdjustmentOnVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_lgn_DebtInstrumentAdditionalSpreadAdjustmentOnVariableRate_019d1aef-4c53-739b-8ced-f33415468923" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019d1aef-4c53-7448-bdee-38e833f812b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019d1aef-4c53-7448-bdee-38e833f812b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019d1aef-4c53-748d-9e87-bb05116c138e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019d1aef-4c53-748d-9e87-bb05116c138e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFeeAmount_019d1aef-752c-7c19-bc03-3d53f121b5b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFeeAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentFeeAmount_019d1aef-752c-7c19-bc03-3d53f121b5b2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_019d1aef-752c-7f86-8cbc-a0afb5260c69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_019d1aef-752c-7f86-8cbc-a0afb5260c69" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019d1aef-752c-7531-bcfc-4d5473d54b10" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019d1aef-752c-7531-bcfc-4d5473d54b10" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LineOfCreditFacilityAmendmentFeeAmount_019d2287-39a4-7d9b-8f9d-36cdfa6a5e2b" xlink:href="lgn-20251231.xsd#lgn_LineOfCreditFacilityAmendmentFeeAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_lgn_LineOfCreditFacilityAmendmentFeeAmount_019d2287-39a4-7d9b-8f9d-36cdfa6a5e2b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d1aef-b4c2-74da-b0d6-1916adeb20ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d1aef-b4c2-74da-b0d6-1916adeb20ca" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DebtInstrumentVariableRateFloor_019d1aef-b4c2-7263-b3a4-1909d0565331" xlink:href="lgn-20251231.xsd#lgn_DebtInstrumentVariableRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_lgn_DebtInstrumentVariableRateFloor_019d1aef-b4c2-7263-b3a4-1909d0565331" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d1aef-b4c2-7a3a-a913-9deb8812b607" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d1aef-b4c2-7a3a-a913-9deb8812b607" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019d1aef-b4c2-7b60-b0b6-7bb62ae307cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-7876-ad7e-f5ca25843ad1" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019d1aef-b4c2-7b60-b0b6-7bb62ae307cd" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DebtRevolvingLineofCreditDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DebtRevolvingLineofCreditDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DebtRevolvingLineofCreditDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019c9a06-b3c5-7c14-a309-be595dca0458" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_us-gaap_CreditFacilityAxis_019c9a06-b3c5-7c14-a309-be595dca0458" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9a06-b3c5-7c14-a309-be595dca0458_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9a06-b3c5-7c14-a309-be595dca0458" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9a06-b3c5-7c14-a309-be595dca0458_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9a06-b3c5-753a-a084-c6e205ba35c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9a06-b3c5-7c14-a309-be595dca0458" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9a06-b3c5-753a-a084-c6e205ba35c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019c9a06-b3c5-721f-b1fd-f6ddcc4fe74f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019c9a06-b3c5-753a-a084-c6e205ba35c8" xlink:to="loc_us-gaap_LineOfCreditMember_019c9a06-b3c5-721f-b1fd-f6ddcc4fe74f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_us-gaap_DebtInstrumentAxis_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9a06-b3c5-7e69-919e-8128070cda06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9a06-b3c5-7ed0-8b63-e1eb99cd9810" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9a06-b3c5-7e69-919e-8128070cda06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember_019c9a06-b3c5-7267-af37-b87ea58e87c4" xlink:href="lgn-20251231.xsd#lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9a06-b3c5-7e69-919e-8128070cda06" xlink:to="loc_lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember_019c9a06-b3c5-7267-af37-b87ea58e87c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7fc4-8f71-5c3a09cb557a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9a06-b3c5-7e0c-8c59-04c6d5cab20f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7fc4-8f71-5c3a09cb557a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019c9a06-b3c5-7f92-886b-0d4273a5194e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7fc4-8f71-5c3a09cb557a" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019c9a06-b3c5-7f92-886b-0d4273a5194e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019c9a06-b3c5-7653-a157-a6f2dcbb0b09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7fc4-8f71-5c3a09cb557a" xlink:to="loc_us-gaap_SecuredDebtMember_019c9a06-b3c5-7653-a157-a6f2dcbb0b09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_019c9a06-b3c5-7fb3-aea3-43d09a69cc45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9a06-b3c5-7fc4-8f71-5c3a09cb557a" xlink:to="loc_us-gaap_LetterOfCreditMember_019c9a06-b3c5-7fb3-aea3-43d09a69cc45" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019c9a06-b3c5-716f-adce-786a6feb833c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_srt_RangeAxis_019c9a06-b3c5-716f-adce-786a6feb833c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9a06-b3c5-716f-adce-786a6feb833c_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019c9a06-b3c5-716f-adce-786a6feb833c" xlink:to="loc_srt_RangeMember_019c9a06-b3c5-716f-adce-786a6feb833c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9a06-b3c5-7d97-a509-910048a1e46b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019c9a06-b3c5-716f-adce-786a6feb833c" xlink:to="loc_srt_RangeMember_019c9a06-b3c5-7d97-a509-910048a1e46b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019c9a06-b3c5-7570-bb26-e03d7e019e0d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c9a06-b3c5-7d97-a509-910048a1e46b" xlink:to="loc_srt_MinimumMember_019c9a06-b3c5-7570-bb26-e03d7e019e0d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019c9a06-b3c5-7137-a26f-1d211f74b31e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c9a06-b3c5-7d97-a509-910048a1e46b" xlink:to="loc_srt_MaximumMember_019c9a06-b3c5-7137-a26f-1d211f74b31e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_us-gaap_VariableRateAxis_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08" xlink:to="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-707a-8cd5-da43a4fad533" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019c9a06-b3c5-7edd-8c93-b6ab78ee5a08" xlink:to="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-707a-8cd5-da43a4fad533" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019c9a06-b3c5-70b4-95e0-fca668410a68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-707a-8cd5-da43a4fad533" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019c9a06-b3c5-70b4-95e0-fca668410a68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019c9a06-b3c5-7e2f-9ee0-abc9f00573b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-707a-8cd5-da43a4fad533" xlink:to="loc_us-gaap_BaseRateMember_019c9a06-b3c5-7e2f-9ee0-abc9f00573b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019d3f4b-2ae3-7a03-b598-37dbe4fb2af2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalFundsEffectiveSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019c9a06-b3c5-707a-8cd5-da43a4fad533" xlink:to="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019d3f4b-2ae3-7a03-b598-37dbe4fb2af2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019c9a06-b3c5-7851-8fbd-239aaba9d8e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7f5b-b81d-c6f9d2bacb50" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019c9a06-b3c5-7851-8fbd-239aaba9d8e3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c9a06-b3c5-7851-8fbd-239aaba9d8e3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c9a06-b3c5-7851-8fbd-239aaba9d8e3" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c9a06-b3c5-7851-8fbd-239aaba9d8e3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c9a06-b3c5-7306-bf8b-8397bc131151" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c9a06-b3c5-7851-8fbd-239aaba9d8e3" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c9a06-b3c5-7306-bf8b-8397bc131151" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019c9a06-b3c5-79fe-9dab-826e2fdaa133" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019c9a06-b3c5-7306-bf8b-8397bc131151" xlink:to="loc_us-gaap_SubsequentEventMember_019c9a06-b3c5-79fe-9dab-826e2fdaa133" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019c9a06-b3c5-7422-a851-49c636f140b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019c9a06-b3c5-7422-a851-49c636f140b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019c9a06-b3c5-7d28-ba93-f2a5e1395792" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019c9a06-b3c5-7d28-ba93-f2a5e1395792" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DebtInstrumentVariableRateFloor_019c9a06-b3c5-78bd-9cc4-993b50448f72" xlink:href="lgn-20251231.xsd#lgn_DebtInstrumentVariableRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_lgn_DebtInstrumentVariableRateFloor_019c9a06-b3c5-78bd-9cc4-993b50448f72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d1acf-95d4-71e9-bda1-071fd0217994" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d1acf-95d4-71e9-bda1-071fd0217994" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019c9a06-b3c5-7b57-9f0a-8e84c6efb582" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019c9a06-b3c5-7b57-9f0a-8e84c6efb582" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019c9a06-b3c5-7611-9bb5-b757fb2b43fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019c9a06-b3c5-7611-9bb5-b757fb2b43fb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_019c9a06-b3c5-7cd2-a998-3fff3c83a57a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_019c9a06-b3c5-7cd2-a998-3fff3c83a57a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019c9a06-b3c5-7e68-b536-6bbba2757af0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019c9a06-b3c5-7e68-b536-6bbba2757af0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019c9a06-b3c5-7108-9971-45fa129fc009" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_LineOfCredit_019c9a06-b3c5-7108-9971-45fa129fc009" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_019c9a06-b3c5-758d-bb38-748df9bce078" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_019c9a06-b3c5-758d-bb38-748df9bce078" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DebtInstrumentCovenantConsolidatedFirstLienNetLeverageRatioMaximum_019c9a06-b3c5-7811-9cbd-e9be82e2fa86" xlink:href="lgn-20251231.xsd#lgn_DebtInstrumentCovenantConsolidatedFirstLienNetLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_lgn_DebtInstrumentCovenantConsolidatedFirstLienNetLeverageRatioMaximum_019c9a06-b3c5-7811-9cbd-e9be82e2fa86" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DebtInstrumentThresholdToTestNetLeverageRatioOutstandingBorrowingsComparedToFacilitySizePercentMinimum_019c9a06-b3c5-7470-b5a9-d39d1634d73a" xlink:href="lgn-20251231.xsd#lgn_DebtInstrumentThresholdToTestNetLeverageRatioOutstandingBorrowingsComparedToFacilitySizePercentMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-73a6-bad9-076d719df98c" xlink:to="loc_lgn_DebtInstrumentThresholdToTestNetLeverageRatioOutstandingBorrowingsComparedToFacilitySizePercentMinimum_019c9a06-b3c5-7470-b5a9-d39d1634d73a" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DebtNotesPayableDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DebtNotesPayableDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DebtNotesPayableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019c9a07-6323-7552-8050-3fd2d56694d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:to="loc_us-gaap_DebtInstrumentAxis_019c9a07-6323-7552-8050-3fd2d56694d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7552-8050-3fd2d56694d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9a07-6323-7552-8050-3fd2d56694d2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7552-8050-3fd2d56694d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7d3b-9c45-eff9128d3378" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9a07-6323-7552-8050-3fd2d56694d2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7d3b-9c45-eff9128d3378" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember_019c9a07-6323-7b3a-9432-f75ed4f22cbb" xlink:href="lgn-20251231.xsd#lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7d3b-9c45-eff9128d3378" xlink:to="loc_lgn_PromissoryNotePayableInConnectionWith2023AcquisitionMember_019c9a07-6323-7b3a-9432-f75ed4f22cbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PromissoryNotePayableInConnectionWith2024And2022AcquisitionMember_019cde34-de32-76df-99c5-89dcaf5d7b5d" xlink:href="lgn-20251231.xsd#lgn_PromissoryNotePayableInConnectionWith2024And2022AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9a07-6323-7d3b-9c45-eff9128d3378" xlink:to="loc_lgn_PromissoryNotePayableInConnectionWith2024And2022AcquisitionMember_019cde34-de32-76df-99c5-89dcaf5d7b5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019c9a07-6323-7835-8ba6-9cd4a929b767" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019c9a07-6323-7835-8ba6-9cd4a929b767" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-7835-8ba6-9cd4a929b767_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9a07-6323-7835-8ba6-9cd4a929b767" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-7835-8ba6-9cd4a929b767_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-759a-a9c4-9bc04d498f21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9a07-6323-7835-8ba6-9cd4a929b767" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-759a-a9c4-9bc04d498f21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019c9a07-6323-7322-a52f-856629889b87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-759a-a9c4-9bc04d498f21" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019c9a07-6323-7322-a52f-856629889b87" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InsuranceRelatedPaymentsMember_019c9a07-a53c-7b6f-b88d-ccf2beb0c473" xlink:href="lgn-20251231.xsd#lgn_InsuranceRelatedPaymentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9a07-6323-759a-a9c4-9bc04d498f21" xlink:to="loc_lgn_InsuranceRelatedPaymentsMember_019c9a07-a53c-7b6f-b88d-ccf2beb0c473" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019c9a07-6323-7794-9e11-b7921aa4744a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019c9a07-6323-7794-9e11-b7921aa4744a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c9a07-6323-7794-9e11-b7921aa4744a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019c9a07-6323-7794-9e11-b7921aa4744a" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c9a07-6323-7794-9e11-b7921aa4744a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019cde47-bd31-7201-8ad4-e515c2537a28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019c9a07-6323-7794-9e11-b7921aa4744a" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019cde47-bd31-7201-8ad4-e515c2537a28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c9a07-6323-77b2-af53-663344805dba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019cde47-bd31-7201-8ad4-e515c2537a28" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c9a07-6323-77b2-af53-663344805dba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019c9a07-6323-775d-a431-4204bae0d4cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c9a07-6323-77b2-af53-663344805dba" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019c9a07-6323-775d-a431-4204bae0d4cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019c9a07-a53c-7dae-a212-3c1c48c0517f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019b6cec-7d93-7b63-b582-0c70e5b2a7d7" xlink:to="loc_srt_RangeAxis_019c9a07-a53c-7dae-a212-3c1c48c0517f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9a07-a53c-7dae-a212-3c1c48c0517f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019c9a07-a53c-7dae-a212-3c1c48c0517f" xlink:to="loc_srt_RangeMember_019c9a07-a53c-7dae-a212-3c1c48c0517f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9a07-a53c-79e5-b128-6b45fd072d16" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019c9a07-a53c-7dae-a212-3c1c48c0517f" xlink:to="loc_srt_RangeMember_019c9a07-a53c-79e5-b128-6b45fd072d16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019c9a07-a53c-7650-b690-364a37f3614f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c9a07-a53c-79e5-b128-6b45fd072d16" xlink:to="loc_srt_MinimumMember_019c9a07-a53c-7650-b690-364a37f3614f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019c9a07-a53c-73c0-8aa2-e12341cfc3a1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c9a07-a53c-79e5-b128-6b45fd072d16" xlink:to="loc_srt_MaximumMember_019c9a07-a53c-73c0-8aa2-e12341cfc3a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019c9a07-6323-7ff9-9ccc-d40a455b0c84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019c9a07-6323-7ff9-9ccc-d40a455b0c84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_019c9a07-6323-7c76-92bd-4309b3231509" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentFairValue_019c9a07-6323-7c76-92bd-4309b3231509" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9a07-6323-78bc-9068-45749e4a83b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9a07-6323-78bc-9068-45749e4a83b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_019c9a07-6323-7aa8-9fc3-5fd1c36234fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentTerm_019c9a07-6323-7aa8-9fc3-5fd1c36234fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermNotesPayable_019c9a07-a53c-7d06-b436-e1f15623b448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_LongTermNotesPayable_019c9a07-a53c-7d06-b436-e1f15623b448" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableCurrent_019c9a07-a53c-7419-9851-13d53da33875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_NotesPayableCurrent_019c9a07-a53c-7419-9851-13d53da33875" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019c9a07-a53c-7922-bad7-3ca9fdb0591d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_LongTermDebtCurrent_019c9a07-a53c-7922-bad7-3ca9fdb0591d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019c9a07-a53c-74ab-92e6-05bfa810922a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019b6cec-7d93-78c7-9ffb-cfb1a618118b" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019c9a07-a53c-74ab-92e6-05bfa810922a" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/FairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#FairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/FairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019b6cf6-d499-7b78-b312-0c326d3ce628" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019b6cf6-d499-7b81-969b-3578b76072f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019b6cf6-d499-7b78-b312-0c326d3ce628" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019b6cf6-d499-7b81-969b-3578b76072f7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019b6cf6-d499-7bfb-a86d-8b5d1a62e164" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019b6cf6-d499-7b81-969b-3578b76072f7" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019b6cf6-d499-7bfb-a86d-8b5d1a62e164" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019b6cf6-d499-7bfb-a86d-8b5d1a62e164_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019b6cf6-d499-7bfb-a86d-8b5d1a62e164" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019b6cf6-d499-7bfb-a86d-8b5d1a62e164_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019b6cf6-d499-76ad-abda-2fd1ea9f86c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019b6cf6-d499-7bfb-a86d-8b5d1a62e164" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019b6cf6-d499-76ad-abda-2fd1ea9f86c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019b6cf6-d499-712a-97a3-beb2c09d9cc9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019b6cf6-d499-76ad-abda-2fd1ea9f86c6" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019b6cf6-d499-712a-97a3-beb2c09d9cc9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019b6cf6-d499-7b8f-bcdf-b5a324502009" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019b6cf6-d499-7b81-969b-3578b76072f7" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019b6cf6-d499-7b8f-bcdf-b5a324502009" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7b8f-bcdf-b5a324502009_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019b6cf6-d499-7b8f-bcdf-b5a324502009" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7b8f-bcdf-b5a324502009_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7edd-bdca-24ec3a5532db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019b6cf6-d499-7b8f-bcdf-b5a324502009" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7edd-bdca-24ec3a5532db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019b6cf6-d499-7b17-9c84-130c7e820b00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7edd-bdca-24ec3a5532db" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019b6cf6-d499-7b17-9c84-130c7e820b00" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019b6cf6-d499-766d-86c1-474212d01b48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7edd-bdca-24ec3a5532db" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019b6cf6-d499-766d-86c1-474212d01b48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019b6cf6-d499-7aa9-b7ed-40128a5472be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019b6cf6-d499-7edd-bdca-24ec3a5532db" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019b6cf6-d499-7aa9-b7ed-40128a5472be" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019b6cf6-d499-7733-8389-438284f533c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019b6cf6-d499-7b78-b312-0c326d3ce628" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019b6cf6-d499-7733-8389-438284f533c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019b6cf6-d499-77e3-b857-38cb2b201dc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019b6cf6-d499-7b78-b312-0c326d3ce628" xlink:to="loc_us-gaap_DerivativeAssets_019b6cf6-d499-77e3-b857-38cb2b201dc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019b6cf6-d499-7e1a-bb4c-84082e8386e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019b6cf6-d499-7b78-b312-0c326d3ce628" xlink:to="loc_us-gaap_DerivativeLiabilities_019b6cf6-d499-7e1a-bb4c-84082e8386e2" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/FairValueMeasurementsSummaryofChangesinContingentConsiderationLiabilitiesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#FairValueMeasurementsSummaryofChangesinContingentConsiderationLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/FairValueMeasurementsSummaryofChangesinContingentConsiderationLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f52-6faa-7a25-b5ad-aa8b9f22b39f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f53-56fd-7125-aba6-fc84da066839" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f52-6faa-7a25-b5ad-aa8b9f22b39f" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f53-56fd-7125-aba6-fc84da066839" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_019b6f54-1cbc-71b3-badf-aefcdd22ef78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f53-56fd-7125-aba6-fc84da066839" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_019b6f54-1cbc-71b3-badf-aefcdd22ef78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019b6f54-1cbc-71b3-badf-aefcdd22ef78_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019b6f54-1cbc-71b3-badf-aefcdd22ef78" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019b6f54-1cbc-71b3-badf-aefcdd22ef78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019b6f54-49ce-7624-a8e8-4df940abf449" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019b6f54-1cbc-71b3-badf-aefcdd22ef78" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019b6f54-49ce-7624-a8e8-4df940abf449" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ContingentConsiderationLiabilitiesMember_019b6f56-1328-785f-9d5c-e389e4eea845" xlink:href="lgn-20251231.xsd#lgn_ContingentConsiderationLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019b6f54-49ce-7624-a8e8-4df940abf449" xlink:to="loc_lgn_ContingentConsiderationLiabilitiesMember_019b6f56-1328-785f-9d5c-e389e4eea845" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019b6f52-2005-7c1e-b349-23b7d91d411a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f52-6faa-7a25-b5ad-aa8b9f22b39f" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019b6f52-2005-7c1e-b349-23b7d91d411a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019b6f54-bb90-7ad0-9467-0a5379b8f8ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019b6f52-2005-7c1e-b349-23b7d91d411a" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019b6f54-bb90-7ad0-9467-0a5379b8f8ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_019be181-edb3-7c9f-8f22-0559f28faf93" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019b6f52-2005-7c1e-b349-23b7d91d411a" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_019be181-edb3-7c9f-8f22-0559f28faf93" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019b6f54-dbad-762f-a210-1ca7165f8327" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#FairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f5f-6732-7084-9f65-32b6ebbdd00e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f5f-6732-7084-9f65-32b6ebbdd00e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_019c47a4-c13d-7513-ae81-547c20de12ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f5f-6732-7084-9f65-32b6ebbdd00e" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_019c47a4-c13d-7513-ae81-547c20de12ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019c47a4-c13d-7513-ae81-547c20de12ff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019c47a4-c13d-7513-ae81-547c20de12ff" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019c47a4-c13d-7513-ae81-547c20de12ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019c47a4-c13d-76e5-8afc-ff222de0e3c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019c47a4-c13d-7513-ae81-547c20de12ff" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019c47a4-c13d-76e5-8afc-ff222de0e3c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019c47a4-c13d-7baa-9e0c-5ce03d5b6f43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019c47a4-c13d-76e5-8afc-ff222de0e3c4" xlink:to="loc_us-gaap_RelatedPartyMember_019c47a4-c13d-7baa-9e0c-5ce03d5b6f43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d1d12-ddcf-7ce8-80df-c910fde647b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f5f-6732-7084-9f65-32b6ebbdd00e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d1d12-ddcf-7ce8-80df-c910fde647b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d1d12-ddcf-7ce8-80df-c910fde647b0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d1d12-ddcf-7ce8-80df-c910fde647b0" xlink:to="loc_us-gaap_RelatedPartyDomain_019d1d12-ddcf-7ce8-80df-c910fde647b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d1d12-ddcf-7205-a1b5-ec2e541c6e25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d1d12-ddcf-7ce8-80df-c910fde647b0" xlink:to="loc_us-gaap_RelatedPartyDomain_019d1d12-ddcf-7205-a1b5-ec2e541c6e25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d1d3c-40fa-7533-b20b-5a564fdfd61d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d1d12-ddcf-7205-a1b5-ec2e541c6e25" xlink:to="loc_us-gaap_RelatedPartyMember_019d1d3c-40fa-7533-b20b-5a564fdfd61d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019d227e-656c-7fa8-a544-e588bb847ff6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019b6f5f-6732-7084-9f65-32b6ebbdd00e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019d227e-656c-7fa8-a544-e588bb847ff6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d227e-656c-7fa8-a544-e588bb847ff6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d227e-656c-7fa8-a544-e588bb847ff6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d227e-656c-7fa8-a544-e588bb847ff6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d227e-656c-78a5-8c4b-faa00cd74f5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019d227e-656c-7fa8-a544-e588bb847ff6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d227e-656c-78a5-8c4b-faa00cd74f5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A2022BlackBearAcquisitionMember_019cae65-cd8f-737e-90cd-94b583b9a62d" xlink:href="lgn-20251231.xsd#lgn_A2022BlackBearAcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019d227e-656c-78a5-8c4b-faa00cd74f5b" xlink:to="loc_lgn_A2022BlackBearAcquisitionMember_019cae65-cd8f-737e-90cd-94b583b9a62d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019c47a4-c13d-7273-87e8-885f0fd76a73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019c47a4-c13d-7273-87e8-885f0fd76a73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019ce66f-7109-7b6b-96ea-3da265c5e87a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019ce66f-7109-7b6b-96ea-3da265c5e87a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PaymentForContingentConsiderationLiability_019ce670-b932-7f64-a34e-dfcfbc3e4169" xlink:href="lgn-20251231.xsd#lgn_PaymentForContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_lgn_PaymentForContingentConsiderationLiability_019ce670-b932-7f64-a34e-dfcfbc3e4169" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PaymentForContingentConsiderationLiabilityParentInterests_019cade5-2aa2-78f7-bc59-a5550186b0b2" xlink:href="lgn-20251231.xsd#lgn_PaymentForContingentConsiderationLiabilityParentInterests"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_lgn_PaymentForContingentConsiderationLiabilityParentInterests_019cade5-2aa2-78f7-bc59-a5550186b0b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NoncashPaymentsBusinessCombinationContingentConsiderationLiabilityParentInterestsToRelatedPartyShares_019ce675-9510-7cdf-832d-74eb40a761e2" xlink:href="lgn-20251231.xsd#lgn_NoncashPaymentsBusinessCombinationContingentConsiderationLiabilityParentInterestsToRelatedPartyShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019b6f5f-6732-7d36-804b-df201227c357" xlink:to="loc_lgn_NoncashPaymentsBusinessCombinationContingentConsiderationLiabilityParentInterestsToRelatedPartyShares_019ce675-9510-7cdf-832d-74eb40a761e2" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/FairValueMeasurementsScheduleofCarryingValuesandFairValuesofDebtInstrumentsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#FairValueMeasurementsScheduleofCarryingValuesandFairValuesofDebtInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/FairValueMeasurementsScheduleofCarryingValuesandFairValuesofDebtInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019c7c92-ee71-73ed-8105-7f64e51e2273" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019c7c90-eedf-7433-b48d-f2216eff49b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019c7c92-ee71-73ed-8105-7f64e51e2273" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019c7c90-eedf-7433-b48d-f2216eff49b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019c47a4-c13d-755d-b986-c49f6f806668" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019c7c90-eedf-7433-b48d-f2216eff49b3" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019c47a4-c13d-755d-b986-c49f6f806668" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-755d-b986-c49f6f806668_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019c47a4-c13d-755d-b986-c49f6f806668" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-755d-b986-c49f6f806668_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019ce377-108a-706b-afc3-df339d8d7ff6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019c47a4-c13d-755d-b986-c49f6f806668" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019ce377-108a-706b-afc3-df339d8d7ff6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-7836-bd54-c0f34cbc2938" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019ce377-108a-706b-afc3-df339d8d7ff6" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-7836-bd54-c0f34cbc2938" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019c47a4-c13d-7fde-b1c9-ce152fe41462" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-7836-bd54-c0f34cbc2938" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019c47a4-c13d-7fde-b1c9-ce152fe41462" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019c47a4-c13d-7679-b6ce-2cc0ed4a8fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019c47a4-c13d-7836-bd54-c0f34cbc2938" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019c47a4-c13d-7679-b6ce-2cc0ed4a8fb3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019c47a4-c13d-7db2-89e3-62103a6957ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019c7c90-eedf-7433-b48d-f2216eff49b3" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019c47a4-c13d-7db2-89e3-62103a6957ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-7db2-89e3-62103a6957ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c47a4-c13d-7db2-89e3-62103a6957ae" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-7db2-89e3-62103a6957ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-78fe-af2c-31d8195cf896" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c47a4-c13d-7db2-89e3-62103a6957ae" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-78fe-af2c-31d8195cf896" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019c47a4-c13d-78cc-b55d-4b9dbc6e96f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-78fe-af2c-31d8195cf896" xlink:to="loc_us-gaap_SecuredDebtMember_019c47a4-c13d-78cc-b55d-4b9dbc6e96f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableOtherPayablesMember_019c47a4-c13d-7799-9787-8fadc16928b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableOtherPayablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c47a4-c13d-78fe-af2c-31d8195cf896" xlink:to="loc_us-gaap_NotesPayableOtherPayablesMember_019c47a4-c13d-7799-9787-8fadc16928b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_019c47a4-c13d-71d0-b99b-2dca4e77710a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019c7c92-ee71-73ed-8105-7f64e51e2273" xlink:to="loc_us-gaap_DebtInstrumentFairValue_019c47a4-c13d-71d0-b99b-2dca4e77710a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DerivativesNarrativesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DerivativesNarrativesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DerivativesNarrativesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-746d-82d6-fa5143d9cb11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7736-a3ec-f3f5e9e6a62f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-746d-82d6-fa5143d9cb11" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7736-a3ec-f3f5e9e6a62f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7018-9996-bdea97afb67c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7736-a3ec-f3f5e9e6a62f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7018-9996-bdea97afb67c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-7018-9996-bdea97afb67c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7018-9996-bdea97afb67c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-7018-9996-bdea97afb67c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71bb-a81b-6985ce24f72f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7018-9996-bdea97afb67c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71bb-a81b-6985ce24f72f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019b6a1c-574a-7655-9133-b875de26d1ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71bb-a81b-6985ce24f72f" xlink:to="loc_us-gaap_InterestRateSwapMember_019b6a1c-574a-7655-9133-b875de26d1ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019b6a1c-574a-7fa6-a036-4ab4316799dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-746d-82d6-fa5143d9cb11" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019b6a1c-574a-7fa6-a036-4ab4316799dc" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DerivativesScheduleofFairValueofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DerivativesScheduleofFairValueofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DerivativesScheduleofFairValueofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7030-8f07-18905d541aa8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7030-8f07-18905d541aa8" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_019b6a1c-574a-788e-b8cd-6a1611f4b3fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_019b6a1c-574a-788e-b8cd-6a1611f4b3fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-788e-b8cd-6a1611f4b3fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_019b6a1c-574a-788e-b8cd-6a1611f4b3fc" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-788e-b8cd-6a1611f4b3fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_019b6a1c-574a-788e-b8cd-6a1611f4b3fc" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_019b6a1c-574a-7a7a-81b5-be8e259daa78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:to="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_019b6a1c-574a-7a7a-81b5-be8e259daa78" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentAssetsMember_019b6a1c-574a-7c76-a389-71bce07a4506" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:to="loc_us-gaap_OtherNoncurrentAssetsMember_019b6a1c-574a-7c76-a389-71bce07a4506" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AccruedAndOtherCurrentLiabilitiesMember_019b6a1c-574a-7317-bc67-68a2c505123f" xlink:href="lgn-20251231.xsd#lgn_AccruedAndOtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:to="loc_lgn_AccruedAndOtherCurrentLiabilitiesMember_019b6a1c-574a-7317-bc67-68a2c505123f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_019b6a1c-574a-7be1-80cb-020665b6ef97" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_019b6a1c-574a-73b1-9ad3-82fdf5712d55" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_019b6a1c-574a-7be1-80cb-020665b6ef97" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7969-b303-2ee722b1036f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7969-b303-2ee722b1036f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-7969-b303-2ee722b1036f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7969-b303-2ee722b1036f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-7969-b303-2ee722b1036f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-70fa-8f9b-a5071e9ca5e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-7969-b303-2ee722b1036f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-70fa-8f9b-a5071e9ca5e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019b6a1c-574a-7965-ac76-3ea278cf83d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-70fa-8f9b-a5071e9ca5e6" xlink:to="loc_us-gaap_InterestRateSwapMember_019b6a1c-574a-7965-ac76-3ea278cf83d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7255-9b7c-5a2a4469f3a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:to="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7255-9b7c-5a2a4469f3a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-7255-9b7c-5a2a4469f3a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7255-9b7c-5a2a4469f3a1" xlink:to="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-7255-9b7c-5a2a4469f3a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-72e1-98c9-1d516e9c2c63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7255-9b7c-5a2a4469f3a1" xlink:to="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-72e1-98c9-1d516e9c2c63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019b6a1c-574a-7c98-bee1-c8928dd39ac8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-72e1-98c9-1d516e9c2c63" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019b6a1c-574a-7c98-bee1-c8928dd39ac8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7982-b88a-cb18d3b42612" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7982-b88a-cb18d3b42612" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7982-b88a-cb18d3b42612_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7982-b88a-cb18d3b42612" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7982-b88a-cb18d3b42612_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7379-ac5d-ed142112e417" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7982-b88a-cb18d3b42612" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7379-ac5d-ed142112e417" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019b6a1c-574a-76e8-a5ce-3f159de4e2de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7379-ac5d-ed142112e417" xlink:to="loc_us-gaap_CashFlowHedgingMember_019b6a1c-574a-76e8-a5ce-3f159de4e2de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d1d3e-1454-7ba3-bb73-6fd8daacac1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7548-9240-1a3fa31b3507" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d1d3e-1454-7ba3-bb73-6fd8daacac1c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d1d3e-1454-7ba3-bb73-6fd8daacac1c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d1d3e-1454-7ba3-bb73-6fd8daacac1c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d1d3e-1454-7ba3-bb73-6fd8daacac1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d1d3e-1454-7f29-952a-2b21e79f72ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019d1d3e-1454-7ba3-bb73-6fd8daacac1c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d1d3e-1454-7f29-952a-2b21e79f72ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019d1d3e-1454-7f86-b694-55bb61321e30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019d1d3e-1454-7f29-952a-2b21e79f72ab" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019d1d3e-1454-7f86-b694-55bb61321e30" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019b6a1c-574a-7106-9a81-b9de70f8506d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7030-8f07-18905d541aa8" xlink:to="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019b6a1c-574a-7106-9a81-b9de70f8506d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019b6a1c-574a-704d-9ad6-ac7d3c8a8346" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7030-8f07-18905d541aa8" xlink:to="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019b6a1c-574a-704d-9ad6-ac7d3c8a8346" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019d1d3e-d31b-7763-a150-dd3e86b5ca5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7030-8f07-18905d541aa8" xlink:to="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019d1d3e-d31b-7763-a150-dd3e86b5ca5b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DerivativesScheduleofCashFlowHedgesIncludedinAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DerivativesScheduleofCashFlowHedgesIncludedinAccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DerivativesScheduleofCashFlowHedgesIncludedinAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7d37-8d5b-655f55749605" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-79e7-9c4a-39d5adf83f61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7d37-8d5b-655f55749605" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-79e7-9c4a-39d5adf83f61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019b6a1c-574a-799f-8fa4-6b098a07759c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-79e7-9c4a-39d5adf83f61" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019b6a1c-574a-799f-8fa4-6b098a07759c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-799f-8fa4-6b098a07759c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019b6a1c-574a-799f-8fa4-6b098a07759c" xlink:to="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-799f-8fa4-6b098a07759c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-755e-b062-fb10c6aa3143" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019b6a1c-574a-799f-8fa4-6b098a07759c" xlink:to="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-755e-b062-fb10c6aa3143" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019b6a1c-574a-77bc-b119-4c867d1a8f7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-755e-b062-fb10c6aa3143" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019b6a1c-574a-77bc-b119-4c867d1a8f7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_019b6a1c-574a-78c2-9943-b399a8fa5de1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-755e-b062-fb10c6aa3143" xlink:to="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_019b6a1c-574a-78c2-9943-b399a8fa5de1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_019b6a1c-574a-7b28-8471-559c820be69b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019b6a1c-574a-755e-b062-fb10c6aa3143" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_019b6a1c-574a-7b28-8471-559c820be69b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-7d37-8d5b-655f55749605" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6a1c-574a-76d4-b02d-1c30ef18e23a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6a1c-574a-76d4-b02d-1c30ef18e23a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019be12d-8812-7df8-ada9-6eae515d7dc7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019be12d-8812-7df8-ada9-6eae515d7dc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019b6a1c-574a-734d-aa2d-803bde8392cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019b6a1c-574a-734d-aa2d-803bde8392cc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019b6a1c-574a-7fa3-aaf2-17d7deaa059a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019b6a1c-574a-7fa3-aaf2-17d7deaa059a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019b6a1c-574a-768d-a3fa-cc4ffe4d8bf4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019b6a1c-574a-7a8b-8983-a7ca2a6eadd4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019b6a1c-574a-768d-a3fa-cc4ffe4d8bf4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019b6a1c-574a-7c54-9625-445f0f1c483f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019be12d-e47f-79e2-8af7-f3f8e9dfb2ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/DerivativesScheduleofInterestRateSwapAgreementsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#DerivativesScheduleofInterestRateSwapAgreementsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/DerivativesScheduleofInterestRateSwapAgreementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-76a6-bded-24830552a688" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-76a6-bded-24830552a688" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-708c-ace2-13b867a020ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-708c-ace2-13b867a020ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-708c-ace2-13b867a020ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-708c-ace2-13b867a020ab" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-708c-ace2-13b867a020ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019b6a1c-574a-708c-ace2-13b867a020ab" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A3.4396InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7d5a-8cf1-2b798c24852c" xlink:href="lgn-20251231.xsd#lgn_A3.4396InterestRateSwapMaturingAtDecember2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A3.4396InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7d5a-8cf1-2b798c24852c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A3.3750InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7a33-8422-8449af189a79" xlink:href="lgn-20251231.xsd#lgn_A3.3750InterestRateSwapMaturingAtDecember2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A3.3750InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7a33-8422-8449af189a79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InterestRateSwapMaturesBetweenJanuary2024ToSeptember2025Member_019c0f41-468a-7d39-bc40-65c477953538" xlink:href="lgn-20251231.xsd#lgn_InterestRateSwapMaturesBetweenJanuary2024ToSeptember2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_InterestRateSwapMaturesBetweenJanuary2024ToSeptember2025Member_019c0f41-468a-7d39-bc40-65c477953538" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InterestRateSwapMaturesBetweenSeptember2025ToDecember2026Member_019c0f41-7dcc-798d-bcca-883b61c317a6" xlink:href="lgn-20251231.xsd#lgn_InterestRateSwapMaturesBetweenSeptember2025ToDecember2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_InterestRateSwapMaturesBetweenSeptember2025ToDecember2026Member_019c0f41-7dcc-798d-bcca-883b61c317a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A4.0433InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7102-9af4-0a3997b88db2" xlink:href="lgn-20251231.xsd#lgn_A4.0433InterestRateSwapMaturingAtDecember2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A4.0433InterestRateSwapMaturingAtDecember2026Member_019b6a1c-574a-7102-9af4-0a3997b88db2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A3.2480InterestRateSwapMaturingAtDecember2027Member_019b6a1c-574a-74d9-88d6-2b6e2273d72c" xlink:href="lgn-20251231.xsd#lgn_A3.2480InterestRateSwapMaturingAtDecember2027Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A3.2480InterestRateSwapMaturingAtDecember2027Member_019b6a1c-574a-74d9-88d6-2b6e2273d72c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A0.8325InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-7417-a49d-2d49c4fcfceb" xlink:href="lgn-20251231.xsd#lgn_A0.8325InterestRateSwapMaturingAtJanuary2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A0.8325InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-7417-a49d-2d49c4fcfceb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A1.1740InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-73af-8edd-2d35eccc96b1" xlink:href="lgn-20251231.xsd#lgn_A1.1740InterestRateSwapMaturingAtJanuary2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A1.1740InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-73af-8edd-2d35eccc96b1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A1.1732InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-7a51-93a1-67d6cbe12437" xlink:href="lgn-20251231.xsd#lgn_A1.1732InterestRateSwapMaturingAtJanuary2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A1.1732InterestRateSwapMaturingAtJanuary2025Member_019b6a1c-574a-7a51-93a1-67d6cbe12437" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InterestRateSwapMaturesBetweenJanuary2023ToJanuary2025Member_019b6a1c-574a-7e8d-b7fe-536f8b8865c7" xlink:href="lgn-20251231.xsd#lgn_InterestRateSwapMaturesBetweenJanuary2023ToJanuary2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_InterestRateSwapMaturesBetweenJanuary2023ToJanuary2025Member_019b6a1c-574a-7e8d-b7fe-536f8b8865c7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InterestRateSwapMaturesBetweenFebruary12025ToDecember312026Member_019b6a1c-574a-73e8-bdf5-23b9fb73e4ab" xlink:href="lgn-20251231.xsd#lgn_InterestRateSwapMaturesBetweenFebruary12025ToDecember312026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_InterestRateSwapMaturesBetweenFebruary12025ToDecember312026Member_019b6a1c-574a-73e8-bdf5-23b9fb73e4ab" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A3.4581InterestRateSwapMaturingAtDecember2028Member_019d1aff-6f79-74d2-90da-e1cfcd6e256a" xlink:href="lgn-20251231.xsd#lgn_A3.4581InterestRateSwapMaturingAtDecember2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A3.4581InterestRateSwapMaturingAtDecember2028Member_019d1aff-6f79-74d2-90da-e1cfcd6e256a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A3.6995InterestRateSwapMaturingAtDecember2028Member_019d3f44-e51e-7d32-87af-7a42b12d7db0" xlink:href="lgn-20251231.xsd#lgn_A3.6995InterestRateSwapMaturingAtDecember2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019b6a1c-574a-71b4-b7fb-56a088fa40fa" xlink:to="loc_lgn_A3.6995InterestRateSwapMaturingAtDecember2028Member_019d3f44-e51e-7d32-87af-7a42b12d7db0" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7a25-92d4-20c5c755d9d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7a25-92d4-20c5c755d9d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7a25-92d4-20c5c755d9d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7a25-92d4-20c5c755d9d2" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-7a25-92d4-20c5c755d9d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-708e-8d90-184bc93e8a69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019b6a1c-574a-7a25-92d4-20c5c755d9d2" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-708e-8d90-184bc93e8a69" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019b6a1c-574a-71aa-85dd-3ff755369964" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019b6a1c-574a-708e-8d90-184bc93e8a69" xlink:to="loc_us-gaap_CashFlowHedgingMember_019b6a1c-574a-71aa-85dd-3ff755369964" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7908-baa6-885389e5b981" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:to="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7908-baa6-885389e5b981" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-7908-baa6-885389e5b981_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7908-baa6-885389e5b981" xlink:to="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-7908-baa6-885389e5b981_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-76fc-bd71-99aaed4d9a21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019b6a1c-574a-7908-baa6-885389e5b981" xlink:to="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-76fc-bd71-99aaed4d9a21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019b6a1c-574a-7dd5-8bfc-20d1984dad94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019b6a1c-574a-76fc-bd71-99aaed4d9a21" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019b6a1c-574a-7dd5-8bfc-20d1984dad94" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019d1e5b-adc4-7bc4-b560-4ccd23803e43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019b6a1c-574a-7184-9cf9-c4975cadfd0d" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019d1e5b-adc4-7bc4-b560-4ccd23803e43" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019d1e5b-adc4-7bc4-b560-4ccd23803e43_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019d1e5b-adc4-7bc4-b560-4ccd23803e43" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019d1e5b-adc4-7bc4-b560-4ccd23803e43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019d1e5b-adc4-7a20-9c96-e70ba2a44007" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019d1e5b-adc4-7bc4-b560-4ccd23803e43" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019d1e5b-adc4-7a20-9c96-e70ba2a44007" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019d1e5b-c402-7efe-9622-102ef9652c3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019d1e5b-adc4-7a20-9c96-e70ba2a44007" xlink:to="loc_us-gaap_SubsequentEventMember_019d1e5b-c402-7efe-9622-102ef9652c3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019b6a1c-574a-706f-aaae-0dfcbe7d8056" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-76a6-bded-24830552a688" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019b6a1c-574a-706f-aaae-0dfcbe7d8056" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_019b6a1c-574a-7b99-80f0-e2aebaf79aa6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-76a6-bded-24830552a688" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_019b6a1c-574a-7b99-80f0-e2aebaf79aa6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DerivativeIncreaseDecreaseInNotionalAmountSingleInstrument_019c0f43-4fde-7256-8f80-fc96ed7dd50a" xlink:href="lgn-20251231.xsd#lgn_DerivativeIncreaseDecreaseInNotionalAmountSingleInstrument"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019b6a1c-574a-76a6-bded-24830552a688" xlink:to="loc_lgn_DerivativeIncreaseDecreaseInNotionalAmountSingleInstrument_019c0f43-4fde-7256-8f80-fc96ed7dd50a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockholdersEquityMembersEquityDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockholdersEquityMembersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockholdersEquityMembersEquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_srt_OwnershipAxis_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a" xlink:to="loc_srt_OwnershipDomain_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019cae9a-7ba9-77ad-88eb-a17f1d2cdb28" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019cae9a-7ba9-73c1-8ac6-7ebabb8d020a" xlink:to="loc_srt_OwnershipDomain_019cae9a-7ba9-77ad-88eb-a17f1d2cdb28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceHoldingsLLCMember_019cae9a-7ba9-7df9-ae2f-0ffbf82fe3db" xlink:href="lgn-20251231.xsd#lgn_LegenceHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019cae9a-7ba9-77ad-88eb-a17f1d2cdb28" xlink:to="loc_lgn_LegenceHoldingsLLCMember_019cae9a-7ba9-7df9-ae2f-0ffbf82fe3db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019cae9a-7ba9-72f1-8e81-ccaec1a7b142" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019cae9a-7ba9-72f1-8e81-ccaec1a7b142" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-72f1-8e81-ccaec1a7b142_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cae9a-7ba9-72f1-8e81-ccaec1a7b142" xlink:to="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-72f1-8e81-ccaec1a7b142_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cae9a-7ba9-72f1-8e81-ccaec1a7b142" xlink:to="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNAUnitsMember_019cae9a-7ba9-7a7a-99bc-961d2772df3f" xlink:href="lgn-20251231.xsd#lgn_LGNAUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:to="loc_lgn_LGNAUnitsMember_019cae9a-7ba9-7a7a-99bc-961d2772df3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNBUnitsMember_019cae9a-7ba9-716d-bfe1-e095c7806c91" xlink:href="lgn-20251231.xsd#lgn_LGNBUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:to="loc_lgn_LGNBUnitsMember_019cae9a-7ba9-716d-bfe1-e095c7806c91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019cae9a-7ba9-7a8b-bbbe-a8d6d5b13ebc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:to="loc_us-gaap_CommonClassAMember_019cae9a-7ba9-7a8b-bbbe-a8d6d5b13ebc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019cae9a-7ba9-7102-aad8-640ab1adfce8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cae9a-7ba9-7d59-a5b5-9a6d4c719af3" xlink:to="loc_us-gaap_CommonClassBMember_019cae9a-7ba9-7102-aad8-640ab1adfce8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019cae9a-7ba9-7407-87f5-bac5addff857" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_dei_LegalEntityAxis_019cae9a-7ba9-7407-87f5-bac5addff857" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019cae9a-7ba9-7407-87f5-bac5addff857_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019cae9a-7ba9-7407-87f5-bac5addff857" xlink:to="loc_dei_EntityDomain_019cae9a-7ba9-7407-87f5-bac5addff857_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019cae9a-7ba9-71d3-b5ec-20681730b9c4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019cae9a-7ba9-7407-87f5-bac5addff857" xlink:to="loc_dei_EntityDomain_019cae9a-7ba9-71d3-b5ec-20681730b9c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceParentMember_019cae9a-7ba9-70cc-9406-7ed7c61f5e0f" xlink:href="lgn-20251231.xsd#lgn_LegenceParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019cae9a-7ba9-71d3-b5ec-20681730b9c4" xlink:to="loc_lgn_LegenceParentMember_019cae9a-7ba9-70cc-9406-7ed7c61f5e0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_019cae9a-7ba9-796d-819b-77f7640164fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_019cae9a-7ba9-796d-819b-77f7640164fd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-796d-819b-77f7640164fd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019cae9a-7ba9-796d-819b-77f7640164fd" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-796d-819b-77f7640164fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-7f60-874c-7471af0e0f9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019cae9a-7ba9-796d-819b-77f7640164fd" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-7f60-874c-7471af0e0f9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SecondaryOfferingMember_019cae9a-7ba9-7f47-a0ab-7b4ecea651c5" xlink:href="lgn-20251231.xsd#lgn_SecondaryOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-7f60-874c-7471af0e0f9c" xlink:to="loc_lgn_SecondaryOfferingMember_019cae9a-7ba9-7f47-a0ab-7b4ecea651c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OverAllotmentOptionMember_019cae9a-7ba9-77d1-98cb-618b7f6cbc09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OverAllotmentOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019cae9a-7ba9-7f60-874c-7471af0e0f9c" xlink:to="loc_us-gaap_OverAllotmentOptionMember_019cae9a-7ba9-77d1-98cb-618b7f6cbc09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_019cae9a-7ba9-7079-bcf8-f88fbc3a784d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_AssetAcquisitionAxis_019cae9a-7ba9-7079-bcf8-f88fbc3a784d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019cae9a-7ba9-7079-bcf8-f88fbc3a784d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019cae9a-7ba9-7079-bcf8-f88fbc3a784d" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019cae9a-7ba9-7079-bcf8-f88fbc3a784d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019cae9a-7ba9-74b3-a463-1c360322f0e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019cae9a-7ba9-7079-bcf8-f88fbc3a784d" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019cae9a-7ba9-74b3-a463-1c360322f0e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_A2025AcquisitionsMember_019cae9a-7ba9-7bba-a1a9-fe47013cce7c" xlink:href="lgn-20251231.xsd#lgn_A2025AcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_019cae9a-7ba9-74b3-a463-1c360322f0e7" xlink:to="loc_lgn_A2025AcquisitionsMember_019cae9a-7ba9-7bba-a1a9-fe47013cce7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cae9a-7ba9-7795-81b0-470ca8b0ba74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cae9a-7ba9-7795-81b0-470ca8b0ba74" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cae9a-7ba9-7795-81b0-470ca8b0ba74_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cae9a-7ba9-7795-81b0-470ca8b0ba74" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cae9a-7ba9-7795-81b0-470ca8b0ba74_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cae9a-7ba9-7966-9c57-7114396fd8b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cae9a-7ba9-7795-81b0-470ca8b0ba74" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cae9a-7ba9-7966-9c57-7114396fd8b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cae9a-7ba9-7aa2-ad9b-f45ac6e1384a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cae9a-7ba9-7966-9c57-7114396fd8b8" xlink:to="loc_us-gaap_SubsequentEventMember_019cae9a-7ba9-7aa2-ad9b-f45ac6e1384a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019cf7b7-f73e-7f26-bda1-ae19367cc658" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019cf7b7-f73e-7f26-bda1-ae19367cc658" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019cf7b7-f73e-7f26-bda1-ae19367cc658_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019cf7b7-f73e-7f26-bda1-ae19367cc658" xlink:to="loc_us-gaap_EquityComponentDomain_019cf7b7-f73e-7f26-bda1-ae19367cc658_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019cf7b7-f73e-7880-b906-b622c468f1dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019cf7b7-f73e-7f26-bda1-ae19367cc658" xlink:to="loc_us-gaap_EquityComponentDomain_019cf7b7-f73e-7880-b906-b622c468f1dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019cf7b7-f73e-703e-9b69-dd9b0f7acadd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019cf7b7-f73e-7880-b906-b622c468f1dd" xlink:to="loc_us-gaap_CommonStockMember_019cf7b7-f73e-703e-9b69-dd9b0f7acadd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019b6a1d-8b9d-7828-bd27-fdcb36b792e9" xlink:to="loc_us-gaap_AwardTypeAxis_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d1c07-bea7-7837-b610-4023e51d2a0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019d1c07-bea7-74dc-ae3e-efc6e8f1abf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d1c07-bea7-7837-b610-4023e51d2a0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019d1c07-ff31-70ff-963a-720b0f464e98" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d1c07-bea7-7837-b610-4023e51d2a0d" xlink:to="loc_us-gaap_EmployeeStockMember_019d1c07-ff31-70ff-963a-720b0f464e98" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019cae9a-7ba9-7527-a7ba-619b61fe4aa5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019cae9a-7ba9-7527-a7ba-619b61fe4aa5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019cae9a-7ba9-78b6-9cbd-ac4b55efa294" xlink:href="lgn-20251231.xsd#lgn_LimitedPartnersCapitalUnitConversionRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019cae9a-7ba9-78b6-9cbd-ac4b55efa294" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitOutstanding_019cae9a-7ba9-7bfe-ac25-6ac13d7671c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonUnitOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_CommonUnitOutstanding_019cae9a-7ba9-7bfe-ac25-6ac13d7671c4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019cae9a-7ba9-770d-8361-46184722cf00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019cae9a-7ba9-770d-8361-46184722cf00" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_019cae9a-7ba9-7889-bb79-1f05e78bd5d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_019cae9a-7ba9-7889-bb79-1f05e78bd5d0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019d0be1-707c-7927-91fa-985fc325f37f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019d0be1-707c-7927-91fa-985fc325f37f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019cae9a-7ba9-7180-a434-29d2978c685d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019cae9a-7ba9-7180-a434-29d2978c685d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SaleOfStockOptionPeriod_019cae9a-7ba9-70e4-99a3-7e9842fc0036" xlink:href="lgn-20251231.xsd#lgn_SaleOfStockOptionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_SaleOfStockOptionPeriod_019cae9a-7ba9-70e4-99a3-7e9842fc0036" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SaleOfStockNumberOfSharesIssuedInTransactionExchangedShares_019cf80c-c6a0-7304-a180-ed5b18f04fb1" xlink:href="lgn-20251231.xsd#lgn_SaleOfStockNumberOfSharesIssuedInTransactionExchangedShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_SaleOfStockNumberOfSharesIssuedInTransactionExchangedShares_019cf80c-c6a0-7304-a180-ed5b18f04fb1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_019cae9a-7ba9-70cd-9ecc-2d247cef1bf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_019cae9a-7ba9-70cd-9ecc-2d247cef1bf2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019cae9a-7ba9-764b-8a3c-8de5bc68f021" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019cae9a-7ba9-764b-8a3c-8de5bc68f021" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019cae9a-7ba9-7275-9d65-63201d71dc30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019cae9a-7ba9-7275-9d65-63201d71dc30" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019cae9a-7ba9-7113-8fdb-1a1281b75be8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019cae9a-7ba9-7113-8fdb-1a1281b75be8" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019cae9a-7ba9-7a27-918d-d28d0057388e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019cae9a-7ba9-7a27-918d-d28d0057388e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_CommonStockVotingRightsVotes_019cae9a-7ba9-707d-b68b-e800672a3f5a" xlink:href="lgn-20251231.xsd#lgn_CommonStockVotingRightsVotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_CommonStockVotingRightsVotes_019cae9a-7ba9-707d-b68b-e800672a3f5a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019cae9a-aee8-708b-a4b1-c36fc3f78c0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019cae9a-aee8-708b-a4b1-c36fc3f78c0f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_019cae9a-aee8-7620-9b52-3eab8eb9486e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_019cae9a-aee8-7620-9b52-3eab8eb9486e" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PaymentsForTaxDistributions_019cae9a-aee8-7f36-b7f4-108abb9afbc2" xlink:href="lgn-20251231.xsd#lgn_PaymentsForTaxDistributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_PaymentsForTaxDistributions_019cae9a-aee8-7f36-b7f4-108abb9afbc2" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfCapitalDistribution_019cae9a-aee8-7f0c-bf33-059da2b67b3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfCapitalDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_PaymentsOfCapitalDistribution_019cae9a-aee8-7f0c-bf33-059da2b67b3f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_CapitalDistributionReturnToHolders_019d1a98-9bdf-72ad-ac19-eaa0fc8e04c4" xlink:href="lgn-20251231.xsd#lgn_CapitalDistributionReturnToHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_CapitalDistributionReturnToHolders_019d1a98-9bdf-72ad-ac19-eaa0fc8e04c4" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019d0a3c-c5bd-7b75-8ea7-09beb711b414" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019d0a3c-c5bd-7b75-8ea7-09beb711b414" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_019d1c06-cea5-7f49-a27e-f49fa5c84398" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_019d1c06-cea5-7f49-a27e-f49fa5c84398" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPurchaseValueDuringOfferingPeriodPerEmployee_019d0a3b-32ce-730d-a1e9-fb8ba266d6f1" xlink:href="lgn-20251231.xsd#lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPurchaseValueDuringOfferingPeriodPerEmployee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPurchaseValueDuringOfferingPeriodPerEmployee_019d0a3b-32ce-730d-a1e9-fb8ba266d6f1" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019d1c08-d73c-7fb0-9e3f-60706fe52f47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019b6a1d-8b9e-7951-ae90-7765893ab956" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019d1c08-d73c-7fb0-9e3f-60706fe52f47" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-7842-ab85-9a5ca760d53d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-7842-ab85-9a5ca760d53d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ce132-a33d-7fb0-86ae-337491e454d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-7842-ab85-9a5ca760d53d" xlink:to="loc_us-gaap_AwardTypeAxis_019ce132-a33d-7fb0-86ae-337491e454d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7fb0-86ae-337491e454d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019ce132-a33d-7fb0-86ae-337491e454d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7fb0-86ae-337491e454d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019ce132-a33d-7fb0-86ae-337491e454d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ExitInterestsMember_019ce132-a33d-7785-a3d4-bcb3c59bd04c" xlink:href="lgn-20251231.xsd#lgn_ExitInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_lgn_ExitInterestsMember_019ce132-a33d-7785-a3d4-bcb3c59bd04c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TimeInterestsMember_019ce132-d616-739b-8e38-261662a18411" xlink:href="lgn-20251231.xsd#lgn_TimeInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_lgn_TimeInterestsMember_019ce132-d616-739b-8e38-261662a18411" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PerformanceInterestsMember_019ce133-8dd3-78f3-83fb-0d8b52a8d6da" xlink:href="lgn-20251231.xsd#lgn_PerformanceInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_lgn_PerformanceInterestsMember_019ce133-8dd3-78f3-83fb-0d8b52a8d6da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RestrictedSeriesCInterestsMember_019ce133-8dd3-7f11-b7be-c14759cfb7c7" xlink:href="lgn-20251231.xsd#lgn_RestrictedSeriesCInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_lgn_RestrictedSeriesCInterestsMember_019ce133-8dd3-7f11-b7be-c14759cfb7c7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019ce133-e41a-7491-9eae-c72ab507f73d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019ce133-e41a-7491-9eae-c72ab507f73d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ce133-e41a-776c-ba8a-80e48b261726" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ce132-a33d-7310-9067-d5d0cec12bbc" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ce133-e41a-776c-ba8a-80e48b261726" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusAxis_019ce133-e41a-7adf-958f-edaa9bf2275d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GranteeStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-7842-ab85-9a5ca760d53d" xlink:to="loc_us-gaap_GranteeStatusAxis_019ce133-e41a-7adf-958f-edaa9bf2275d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-7adf-958f-edaa9bf2275d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GranteeStatusAxis_019ce133-e41a-7adf-958f-edaa9bf2275d" xlink:to="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-7adf-958f-edaa9bf2275d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-76ed-980e-e989235eafd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GranteeStatusAxis_019ce133-e41a-7adf-958f-edaa9bf2275d" xlink:to="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-76ed-980e-e989235eafd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_019ce133-e41b-7311-ac18-d65460a9ccdd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedPaymentArrangementEmployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-76ed-980e-e989235eafd3" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_019ce133-e41b-7311-ac18-d65460a9ccdd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_019ce133-e41b-7a2d-9bf5-1aebee2d3666" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedPaymentArrangementNonemployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_019ce133-e41a-76ed-980e-e989235eafd3" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_019ce133-e41b-7a2d-9bf5-1aebee2d3666" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019ce134-09e5-7265-8f36-6de11202ce7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-7842-ab85-9a5ca760d53d" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019ce134-09e5-7265-8f36-6de11202ce7a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7265-8f36-6de11202ce7a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019ce134-09e5-7265-8f36-6de11202ce7a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7265-8f36-6de11202ce7a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7553-8a44-bfcd6c0ca96a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019ce134-09e5-7265-8f36-6de11202ce7a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7553-8a44-bfcd6c0ca96a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019ce134-09e5-7aed-9f8d-31b3a59fc304" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7553-8a44-bfcd6c0ca96a" xlink:to="loc_us-gaap_CostOfSalesMember_019ce134-09e5-7aed-9f8d-31b3a59fc304" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_019ce134-09e5-730c-b80b-5fe25b715035" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019ce134-09e5-7553-8a44-bfcd6c0ca96a" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_019ce134-09e5-730c-b80b-5fe25b715035" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsShareBasedCompensation_019ce132-d616-7055-9dbc-9a2d5a0ae441" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_DividendsShareBasedCompensation_019ce132-d616-7055-9dbc-9a2d5a0ae441" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ce132-d616-7cd9-9a98-c7746eee39e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ce132-d616-7cd9-9a98-c7746eee39e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019ce132-d616-7aa8-b5b4-9d7f89b08cb5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019ce132-d616-7aa8-b5b4-9d7f89b08cb5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019ce132-d616-79b1-958c-8a6eee413375" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019ce132-d616-79b1-958c-8a6eee413375" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ce133-8dd3-767a-a1e4-b3ef4cb96ac4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ce133-8dd3-767a-a1e4-b3ef4cb96ac4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilities_019cf787-7616-7054-b9f8-76403783e5ef" xlink:href="lgn-20251231.xsd#lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilities_019cf787-7616-7054-b9f8-76403783e5ef" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019ce133-e41b-7acd-ada7-f148ed5371c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019ce133-e41b-7acd-ada7-f148ed5371c0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfVestingInstallments_019ce133-e41b-71f5-bb55-5c2e38fdefc2" xlink:href="lgn-20251231.xsd#lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfVestingInstallments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_lgn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfVestingInstallments_019ce133-e41b-71f5-bb55-5c2e38fdefc2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019ce133-e41b-77cc-b7e5-5d638adc90f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019ce133-e41b-77cc-b7e5-5d638adc90f1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019ce134-09e5-7b69-9b0a-0cd35d8be147" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7203-a8db-4f0eae5d795c" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019ce134-09e5-7b69-9b0a-0cd35d8be147" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofActivityOfTheTimeInterestsIssuedDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsScheduleofActivityOfTheTimeInterestsIssuedDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofActivityOfTheTimeInterestsIssuedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7616-9536-e63cab3124f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-734c-8ced-c8f08c10ac7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7616-9536-e63cab3124f9" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-734c-8ced-c8f08c10ac7c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b69fb-711d-74c0-b695-7fa422248736" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b69fb-711d-734c-8ced-c8f08c10ac7c" xlink:to="loc_us-gaap_AwardTypeAxis_019b69fb-711d-74c0-b695-7fa422248736" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-74c0-b695-7fa422248736_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b69fb-711d-74c0-b695-7fa422248736" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-74c0-b695-7fa422248736_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-7a2b-8217-b5510a069a06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b69fb-711d-74c0-b695-7fa422248736" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-7a2b-8217-b5510a069a06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TimeInterestsMember_019b6a16-ea7f-7b8c-a089-81ff540d3370" xlink:href="lgn-20251231.xsd#lgn_TimeInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-7a2b-8217-b5510a069a06" xlink:to="loc_lgn_TimeInterestsMember_019b6a16-ea7f-7b8c-a089-81ff540d3370" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RestrictedSeriesCInterestsMember_019b6a40-2434-7c11-bb37-a296a355cd3b" xlink:href="lgn-20251231.xsd#lgn_RestrictedSeriesCInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b69fb-711d-7a2b-8217-b5510a069a06" xlink:to="loc_lgn_RestrictedSeriesCInterestsMember_019b6a40-2434-7c11-bb37-a296a355cd3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7616-9536-e63cab3124f9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b69fb-711d-7955-978d-152aa3134c1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b69fb-711d-7955-978d-152aa3134c1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019b69fb-711d-7a1e-b08c-e74ab1267806" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019b69fb-711d-7a1e-b08c-e74ab1267806" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019b69fb-711d-76aa-a051-d35ccd59dd4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019b69fb-711d-76aa-a051-d35ccd59dd4b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d241d-4b6d-7bc5-bddc-c8caba29f68c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b69fb-711d-75d1-b9da-d8de419a595c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d241d-4b6d-7bc5-bddc-c8caba29f68c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b69fb-711d-75a0-9df8-caa8fc09c78e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b69fb-711d-7616-9536-e63cab3124f9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b69fb-711d-7407-b0eb-1a3910f92334" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b69fb-711d-7407-b0eb-1a3910f92334" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019b69fb-711d-76a7-9b8b-c704446c50c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019b69fb-711d-76a7-9b8b-c704446c50c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019b69fb-711d-71e2-928b-91d6410882dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019b69fb-711d-71e2-928b-91d6410882dd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2423-ff99-77c7-9fce-fe2c22424ead" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b69fb-711d-7746-be4b-7fe214536f53" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2423-ff99-77c7-9fce-fe2c22424ead" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b69fb-711d-79b1-ab59-643274705a4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofFairValueOfTimeInterestsEstimatedUsingTheOPMDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsScheduleofFairValueOfTimeInterestsEstimatedUsingTheOPMDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofFairValueOfTimeInterestsEstimatedUsingTheOPMDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a1f-ba91-7136-8f9c-a30ed6efea1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a1f-ba91-7136-8f9c-a30ed6efea1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b6a1f-ba91-7049-bc46-b8ba27d632b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a1f-ba91-7136-8f9c-a30ed6efea1e" xlink:to="loc_us-gaap_AwardTypeAxis_019b6a1f-ba91-7049-bc46-b8ba27d632b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7049-bc46-b8ba27d632b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b6a1f-ba91-7049-bc46-b8ba27d632b6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7049-bc46-b8ba27d632b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7906-9d61-69c1684e4ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b6a1f-ba91-7049-bc46-b8ba27d632b6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7906-9d61-69c1684e4ea8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TimeInterestsMember_019b6a23-25b1-7fa6-8905-c5b1d8b104f9" xlink:href="lgn-20251231.xsd#lgn_TimeInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7906-9d61-69c1684e4ea8" xlink:to="loc_lgn_TimeInterestsMember_019b6a23-25b1-7fa6-8905-c5b1d8b104f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RestrictedSeriesCInterestsMember_019b6a57-0bb5-780e-b0dd-d5ec6261bba3" xlink:href="lgn-20251231.xsd#lgn_RestrictedSeriesCInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a1f-ba91-7906-9d61-69c1684e4ea8" xlink:to="loc_lgn_RestrictedSeriesCInterestsMember_019b6a57-0bb5-780e-b0dd-d5ec6261bba3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AssumptionScenarioAxis_019ce13b-1e08-7e7b-943b-f265a68417fa" xlink:href="lgn-20251231.xsd#lgn_AssumptionScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a1f-ba91-7136-8f9c-a30ed6efea1e" xlink:to="loc_lgn_AssumptionScenarioAxis_019ce13b-1e08-7e7b-943b-f265a68417fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-7e7b-943b-f265a68417fa_default" xlink:href="lgn-20251231.xsd#lgn_AssumptionScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lgn_AssumptionScenarioAxis_019ce13b-1e08-7e7b-943b-f265a68417fa" xlink:to="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-7e7b-943b-f265a68417fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-78d5-b1c8-64a1c073a126" xlink:href="lgn-20251231.xsd#lgn_AssumptionScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lgn_AssumptionScenarioAxis_019ce13b-1e08-7e7b-943b-f265a68417fa" xlink:to="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-78d5-b1c8-64a1c073a126" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SettledAfterIPOMember_019ce13b-c6b0-791c-a6ec-c68a66b74afd" xlink:href="lgn-20251231.xsd#lgn_SettledAfterIPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-78d5-b1c8-64a1c073a126" xlink:to="loc_lgn_SettledAfterIPOMember_019ce13b-c6b0-791c-a6ec-c68a66b74afd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RemainOutstandingAfterIPOMember_019ce13c-181a-77b5-8e84-8c001a2da8d5" xlink:href="lgn-20251231.xsd#lgn_RemainOutstandingAfterIPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-78d5-b1c8-64a1c073a126" xlink:to="loc_lgn_RemainOutstandingAfterIPOMember_019ce13c-181a-77b5-8e84-8c001a2da8d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DelayedExitMember_019ce13c-5b6c-7e2f-9528-ad8c24155b49" xlink:href="lgn-20251231.xsd#lgn_DelayedExitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lgn_AssumptionScenarioDomain_019ce13b-1e08-78d5-b1c8-64a1c073a126" xlink:to="loc_lgn_DelayedExitMember_019ce13c-5b6c-7e2f-9528-ad8c24155b49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019b6a1f-ba91-75d3-ade3-2b76236cf1f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019b6a1f-ba91-75d3-ade3-2b76236cf1f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019b6a20-f947-73d5-a117-b7e061e4533a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019b6a20-f947-73d5-a117-b7e061e4533a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019b6a21-4c22-7c63-9638-304f1f38ac50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019b6a21-4c22-7c63-9638-304f1f38ac50" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019b6a22-39b9-712c-a20d-9d9913b79047" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a1f-ba91-75e1-af1e-8c9aa58f053d" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019b6a22-39b9-712c-a20d-9d9913b79047" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofCompensationExpenseAndCorrespondingIncomeTaxBenefitDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsScheduleofCompensationExpenseAndCorrespondingIncomeTaxBenefitDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofCompensationExpenseAndCorrespondingIncomeTaxBenefitDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a2b-63bb-7276-96c3-aadf77eb08fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a2b-63bb-7c1e-a3d3-f1448f931c8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a2b-63bb-7276-96c3-aadf77eb08fc" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a2b-63bb-7c1e-a3d3-f1448f931c8a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019b6a2b-63bb-725f-84f3-df956491b6a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a2b-63bb-7c1e-a3d3-f1448f931c8a" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019b6a2b-63bb-725f-84f3-df956491b6a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-725f-84f3-df956491b6a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019b6a2b-63bb-725f-84f3-df956491b6a2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-725f-84f3-df956491b6a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-78b6-b3af-7d19230b09c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019b6a2b-63bb-725f-84f3-df956491b6a2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-78b6-b3af-7d19230b09c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_019b6a2b-63bb-753e-b574-ca1c1a6a046d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-78b6-b3af-7d19230b09c3" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_019b6a2b-63bb-753e-b574-ca1c1a6a046d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019b6a2c-139c-7792-811a-766226002b29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019b6a2b-63bb-78b6-b3af-7d19230b09c3" xlink:to="loc_us-gaap_CostOfSalesMember_019b6a2c-139c-7792-811a-766226002b29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b6a2b-63bb-7c1e-a3d3-f1448f931c8a" xlink:to="loc_us-gaap_AwardTypeAxis_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-75b6-a5b9-6a3314dce48a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b6a2b-63bb-7e57-b5d1-d6e11b215f2e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-75b6-a5b9-6a3314dce48a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TimeInterestsMember_019b6a2f-627a-7f03-974f-93090fc7ab29" xlink:href="lgn-20251231.xsd#lgn_TimeInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-75b6-a5b9-6a3314dce48a" xlink:to="loc_lgn_TimeInterestsMember_019b6a2f-627a-7f03-974f-93090fc7ab29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PerformanceInterestsMember_019ce125-f764-7d2b-aca9-c37264432455" xlink:href="lgn-20251231.xsd#lgn_PerformanceInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-75b6-a5b9-6a3314dce48a" xlink:to="loc_lgn_PerformanceInterestsMember_019ce125-f764-7d2b-aca9-c37264432455" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_RestrictedSeriesCInterestsMember_019b6a55-d46f-7232-bd60-5bb3791173a8" xlink:href="lgn-20251231.xsd#lgn_RestrictedSeriesCInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b6a2b-63bb-75b6-a5b9-6a3314dce48a" xlink:to="loc_lgn_RestrictedSeriesCInterestsMember_019b6a55-d46f-7232-bd60-5bb3791173a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019b6a2b-63bb-75b8-b647-9ba1c17f8946" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a2b-63bb-7276-96c3-aadf77eb08fc" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019b6a2b-63bb-75b8-b647-9ba1c17f8946" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019b6a2e-5bef-7443-914f-d14f0a8c0853" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b6a2b-63bb-7276-96c3-aadf77eb08fc" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019b6a2e-5bef-7443-914f-d14f0a8c0853" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofRestrictedStockUnitsActivityDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsScheduleofRestrictedStockUnitsActivityDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofRestrictedStockUnitsActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9ba9-ebc4-759c-b5dc-7c92766749a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9ba9-ebc4-79b8-b8b2-742a3780d9b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9ba9-ebc4-759c-b5dc-7c92766749a4" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9ba9-ebc4-79b8-b8b2-742a3780d9b6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9ba9-ebc4-79b8-b8b2-742a3780d9b6" xlink:to="loc_us-gaap_AwardTypeAxis_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9ba9-ebc4-7874-bce6-5d05e79f071f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b9ba9-ebc4-7fdb-8d26-c8178d57ac91" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9ba9-ebc4-7874-bce6-5d05e79f071f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019b9ba9-ebc4-769c-b29f-eba402db3b9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9ba9-ebc4-7874-bce6-5d05e79f071f" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019b9ba9-ebc4-769c-b29f-eba402db3b9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9ba9-ebc4-759c-b5dc-7c92766749a4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b9ba9-ebc4-76b3-a6ec-5602cb59568b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b9ba9-ebc4-76b3-a6ec-5602cb59568b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019b9ba9-ebc4-77e3-bcf2-569507acee89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019b9ba9-ebc4-77e3-bcf2-569507acee89" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019b9ba9-ebc4-76bf-9c3e-52890af807d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019b9ba9-ebc4-76bf-9c3e-52890af807d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019b9ba9-ebc4-7fb1-9485-1dcce5840938" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019b9ba9-ebc4-7dea-96e6-281081d9f2f7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019b9ba9-ebc4-7fb1-9485-1dcce5840938" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019b9ba9-ebc4-791c-9731-b7dd18b7e9db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9ba9-ebc4-759c-b5dc-7c92766749a4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7edf-90d8-a8285eb0edea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7edf-90d8-a8285eb0edea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019b9ba9-ebc4-76dc-9039-80d159e072ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019b9ba9-ebc4-76dc-9039-80d159e072ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7033-a442-6a4f04f5cc65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7033-a442-6a4f04f5cc65" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7c3e-bca8-0107338d4969" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019b9ba9-ebc4-7a10-9c7f-dfbb153ede1d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019b9ba9-ebc4-7c3e-bca8-0107338d4969" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019b9ba9-ebc4-79f4-be64-c1dc6db59ff3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofWeightedAverageInputsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#StockBasedCompensationandLongtermIncentiveAwardsScheduleofWeightedAverageInputsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/StockBasedCompensationandLongtermIncentiveAwardsScheduleofWeightedAverageInputsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9baa-472a-7e29-9732-a685ae4086e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9baa-472a-7e29-9732-a685ae4086e8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019b9baa-472a-76fa-af27-441c724e1837" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019b9baa-472a-7e29-9732-a685ae4086e8" xlink:to="loc_us-gaap_AwardTypeAxis_019b9baa-472a-76fa-af27-441c724e1837" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9baa-472a-76fa-af27-441c724e1837_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019b9baa-472a-76fa-af27-441c724e1837" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9baa-472a-76fa-af27-441c724e1837_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9baa-472a-7d5b-95b1-036e8d629a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019b9baa-472a-76fa-af27-441c724e1837" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9baa-472a-7d5b-95b1-036e8d629a9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019b9baa-472a-7569-b4e9-ee3332bd8538" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019b9baa-472a-7d5b-95b1-036e8d629a9e" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019b9baa-472a-7569-b4e9-ee3332bd8538" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_019b9baa-472a-7d10-bfdb-582f00920bb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_SharePrice_019b9baa-472a-7d10-bfdb-582f00920bb2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019b9baa-472a-7b3c-9526-0f76b54cbfaf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019b9baa-472a-7b3c-9526-0f76b54cbfaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019b9baa-472a-7511-b684-e46eb349cfc5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019b9baa-472a-7511-b684-e46eb349cfc5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019b9baa-472a-7c56-ba24-55aa8f20b1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019b9baa-472a-7c56-ba24-55aa8f20b1ad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019b9baa-472a-7f3f-b3fa-1ef5b4ca03cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019b9baa-472a-788a-bcec-e6e70529564b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019b9baa-472a-7f3f-b3fa-1ef5b4ca03cf" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/NoncontrollingInterestsScheduleofOwnershipofLegenceHoldingsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#NoncontrollingInterestsScheduleofOwnershipofLegenceHoldingsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/NoncontrollingInterestsScheduleofOwnershipofLegenceHoldingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7a60-a690-be3d38221133" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7a60-a690-be3d38221133" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7a60-a690-be3d38221133" xlink:to="loc_srt_OwnershipAxis_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820" xlink:to="loc_srt_OwnershipDomain_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019b6d0b-94f9-7ae3-b843-19089c828465" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019b6d0b-94f9-7f06-bb6f-eeaacf8f1820" xlink:to="loc_srt_OwnershipDomain_019b6d0b-94f9-7ae3-b843-19089c828465" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceHoldingsLLCMember_019b6d0b-94f9-7199-9820-a198b30b3a48" xlink:href="lgn-20251231.xsd#lgn_LegenceHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019b6d0b-94f9-7ae3-b843-19089c828465" xlink:to="loc_lgn_LegenceHoldingsLLCMember_019b6d0b-94f9-7199-9820-a198b30b3a48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-7220-ae9b-7d6d55c8efea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7a60-a690-be3d38221133" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-7220-ae9b-7d6d55c8efea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7220-ae9b-7d6d55c8efea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-7220-ae9b-7d6d55c8efea" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7220-ae9b-7d6d55c8efea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7fc9-9bfd-bf21b384b352" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-7220-ae9b-7d6d55c8efea" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7fc9-9bfd-bf21b384b352" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNAUnitsMember_019b6d0b-94f9-7c69-975b-9350b86034c0" xlink:href="lgn-20251231.xsd#lgn_LGNAUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7fc9-9bfd-bf21b384b352" xlink:to="loc_lgn_LGNAUnitsMember_019b6d0b-94f9-7c69-975b-9350b86034c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNBUnitsMember_019b6d0b-94f9-71a0-89af-d301608737fb" xlink:href="lgn-20251231.xsd#lgn_LGNBUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7fc9-9bfd-bf21b384b352" xlink:to="loc_lgn_LGNBUnitsMember_019b6d0b-94f9-71a0-89af-d301608737fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitOutstanding_019b6d0b-94f9-71b8-8819-cc779b719720" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonUnitOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_CommonUnitOutstanding_019b6d0b-94f9-71b8-8819-cc779b719720" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_019cf783-92ba-79c2-862c-450fbb1cb2ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_019cf783-92ba-79c2-862c-450fbb1cb2ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019cf753-fc2e-745a-8a19-2a0d42e33f2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_019cf753-fc2e-745a-8a19-2a0d42e33f2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitOutstanding_019d2638-446a-7ce6-9e2c-2b904ce45bbe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonUnitOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019b6d0b-94f9-7132-a925-fe656f0d6bb4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019b6d0b-94f9-7132-a925-fe656f0d6bb4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_019b6d0b-94f9-78e0-8902-72a392b9f42e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_019b6d0b-94f9-78e0-8902-72a392b9f42e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_StockIssuedDuringPeriodSharesAcquisitionsPercent_019cf7c2-7c75-7058-890a-a93e35edf718" xlink:href="lgn-20251231.xsd#lgn_StockIssuedDuringPeriodSharesAcquisitionsPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_lgn_StockIssuedDuringPeriodSharesAcquisitionsPercent_019cf7c2-7c75-7058-890a-a93e35edf718" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_StockIssuedDuringPeriodSharesConversionOfConvertibleSecuritiesPercent_019cf7c3-7650-74bf-886a-91bb17c12a7c" xlink:href="lgn-20251231.xsd#lgn_StockIssuedDuringPeriodSharesConversionOfConvertibleSecuritiesPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7cf0-a003-3390b19000bd" xlink:to="loc_lgn_StockIssuedDuringPeriodSharesConversionOfConvertibleSecuritiesPercent_019cf7c3-7650-74bf-886a-91bb17c12a7c" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/NoncontrollingInterestsNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#NoncontrollingInterestsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/NoncontrollingInterestsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7b94-aa8c-c398efac7d27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7204-813f-f1fed9d2cbe9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7b94-aa8c-c398efac7d27" xlink:to="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7204-813f-f1fed9d2cbe9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019b6d0b-94f9-7f36-adfc-cad49ab38b0a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7204-813f-f1fed9d2cbe9" xlink:to="loc_srt_OwnershipAxis_019b6d0b-94f9-7f36-adfc-cad49ab38b0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019b6d0b-94f9-7f36-adfc-cad49ab38b0a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019b6d0b-94f9-7f36-adfc-cad49ab38b0a" xlink:to="loc_srt_OwnershipDomain_019b6d0b-94f9-7f36-adfc-cad49ab38b0a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019b6d0b-94f9-7ab0-8d79-ad968984dce6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019b6d0b-94f9-7f36-adfc-cad49ab38b0a" xlink:to="loc_srt_OwnershipDomain_019b6d0b-94f9-7ab0-8d79-ad968984dce6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceHoldingsLLCMember_019b6d0b-94f9-734e-8278-2540de914fda" xlink:href="lgn-20251231.xsd#lgn_LegenceHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019b6d0b-94f9-7ab0-8d79-ad968984dce6" xlink:to="loc_lgn_LegenceHoldingsLLCMember_019b6d0b-94f9-734e-8278-2540de914fda" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-71ba-91b2-0615893cff99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7204-813f-f1fed9d2cbe9" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-71ba-91b2-0615893cff99" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-71ba-91b2-0615893cff99_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-71ba-91b2-0615893cff99" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-71ba-91b2-0615893cff99_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7e40-aa0b-be2890648ab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6d0b-94f9-71ba-91b2-0615893cff99" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7e40-aa0b-be2890648ab4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNBUnitsMember_019b6d0b-94f9-7c86-bbaf-b1c7641d74d8" xlink:href="lgn-20251231.xsd#lgn_LGNBUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6d0b-94f9-7e40-aa0b-be2890648ab4" xlink:to="loc_lgn_LGNBUnitsMember_019b6d0b-94f9-7c86-bbaf-b1c7641d74d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019b6d0b-94f9-7999-9ae7-1c937e592af9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019b6d0b-94f9-7204-813f-f1fed9d2cbe9" xlink:to="loc_dei_LegalEntityAxis_019b6d0b-94f9-7999-9ae7-1c937e592af9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b6d0b-94f9-7999-9ae7-1c937e592af9_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019b6d0b-94f9-7999-9ae7-1c937e592af9" xlink:to="loc_dei_EntityDomain_019b6d0b-94f9-7999-9ae7-1c937e592af9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b6d0b-94f9-7d62-a2d7-fa7773fa1e9e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019b6d0b-94f9-7999-9ae7-1c937e592af9" xlink:to="loc_dei_EntityDomain_019b6d0b-94f9-7d62-a2d7-fa7773fa1e9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LegenceParentMember_019b6d0b-94f9-78d9-b26b-3b4eaee77ab1" xlink:href="lgn-20251231.xsd#lgn_LegenceParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b6d0b-94f9-7d62-a2d7-fa7773fa1e9e" xlink:to="loc_lgn_LegenceParentMember_019b6d0b-94f9-78d9-b26b-3b4eaee77ab1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonUnitOutstanding_019b6d0b-94f9-7bf5-82ad-a1d70ba305ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonUnitOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7b94-aa8c-c398efac7d27" xlink:to="loc_us-gaap_CommonUnitOutstanding_019b6d0b-94f9-7bf5-82ad-a1d70ba305ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019b6d0b-94f9-74c4-b2ef-1fa79e4e9697" xlink:href="lgn-20251231.xsd#lgn_LimitedPartnersCapitalUnitConversionRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019b6d0b-94f9-7b94-aa8c-c398efac7d27" xlink:to="loc_lgn_LimitedPartnersCapitalUnitConversionRatio_019b6d0b-94f9-74c4-b2ef-1fa79e4e9697" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/EarningsPerShareScheduleofComputationofBasicandDilutedEPSDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#EarningsPerShareScheduleofComputationofBasicandDilutedEPSDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/EarningsPerShareScheduleofComputationofBasicandDilutedEPSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicLineItems_019b6cdc-8e2c-7a87-bea4-e47604fffb7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019b6cdc-8e2c-7722-b148-76a11e55a01e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019b6cdc-8e2c-7a87-bea4-e47604fffb7f" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019b6cdc-8e2c-7722-b148-76a11e55a01e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019b6cdc-8e2c-780b-9635-5215aee22f81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019b6cdc-8e2c-7722-b148-76a11e55a01e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019b6cdc-8e2c-780b-9635-5215aee22f81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6cdc-8e2c-780b-9635-5215aee22f81_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6cdc-8e2c-780b-9635-5215aee22f81" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6cdc-8e2c-780b-9635-5215aee22f81_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019b6cdc-8e2c-70df-a154-4755e5053f2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019b6cdc-8e2c-780b-9635-5215aee22f81" xlink:to="loc_us-gaap_ClassOfStockDomain_019b6cdc-8e2c-70df-a154-4755e5053f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019b6cdc-8e2c-76cb-a888-d5f6b13ec80f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019b6cdc-8e2c-70df-a154-4755e5053f2b" xlink:to="loc_us-gaap_CommonClassAMember_019b6cdc-8e2c-76cb-a888-d5f6b13ec80f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019b6cdc-8e2c-7827-a698-bd1297ef69a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019b6cdc-8e2c-7a87-bea4-e47604fffb7f" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019b6cdc-8e2c-7827-a698-bd1297ef69a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019b6cdc-8e2c-7e91-9583-6c8b457f68aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019b6cdc-8e2c-7827-a698-bd1297ef69a9" xlink:to="loc_us-gaap_ProfitLoss_019b6cdc-8e2c-7e91-9583-6c8b457f68aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019b6cdc-8e2c-7fda-b786-f1505e80d67f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019b6cdc-8e2c-7827-a698-bd1297ef69a9" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019b6cdc-8e2c-7fda-b786-f1505e80d67f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019b6cdc-8e2c-7df2-a262-b3799d7be873" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019b6cdc-8e2c-7827-a698-bd1297ef69a9" xlink:to="loc_us-gaap_NetIncomeLoss_019b6cdc-8e2c-7df2-a262-b3799d7be873" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019b6cdc-8e2c-7a87-bea4-e47604fffb7f" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019b6cdc-8e2c-7da0-a10d-6683ea9440c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019b6cdc-8e2c-7da0-a10d-6683ea9440c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019b6cdc-8e2c-7932-8cae-b3e5c357d562" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019b6cdc-8e2c-7932-8cae-b3e5c357d562" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019b6cdc-8e2c-7e88-abe1-923183f6b000" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:to="loc_us-gaap_EarningsPerShareBasic_019b6cdc-8e2c-7e88-abe1-923183f6b000" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019b6cdc-8e2c-7f0f-8837-fd6dbd9ad2f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019b6cdc-8e2c-7509-b4f3-67a9fc7eb4a6" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019b6cdc-8e2c-7f0f-8837-fd6dbd9ad2f0" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/EarningsPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#EarningsPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/EarningsPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019b6cdc-8e2c-73b6-89cc-f897861de118" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019b6cdc-8e2c-744f-a8a5-3f34efcb9a33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019b6cdc-8e2c-73b6-89cc-f897861de118" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019b6cdc-8e2c-744f-a8a5-3f34efcb9a33" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019b6cdc-8e2c-7ee8-9728-01b05dc66865" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019b6cdc-8e2c-744f-a8a5-3f34efcb9a33" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019b6cdc-8e2c-7ee8-9728-01b05dc66865" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7ee8-9728-01b05dc66865_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019b6cdc-8e2c-7ee8-9728-01b05dc66865" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7ee8-9728-01b05dc66865_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7703-8bbf-ac96bd411939" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019b6cdc-8e2c-7ee8-9728-01b05dc66865" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7703-8bbf-ac96bd411939" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019b6cdc-8e2c-7767-806f-79bfab500637" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7703-8bbf-ac96bd411939" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019b6cdc-8e2c-7767-806f-79bfab500637" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019b6cdc-8e2c-7e02-ba1e-ea6181e76de4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7703-8bbf-ac96bd411939" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019b6cdc-8e2c-7e02-ba1e-ea6181e76de4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LGNBUnitsExchangeableForClassACommonStockMember_019b6cdc-8e2c-741c-bafb-efc67ada509b" xlink:href="lgn-20251231.xsd#lgn_LGNBUnitsExchangeableForClassACommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019b6cdc-8e2c-7703-8bbf-ac96bd411939" xlink:to="loc_lgn_LGNBUnitsExchangeableForClassACommonStockMember_019b6cdc-8e2c-741c-bafb-efc67ada509b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019b6cdc-8e2c-7851-bb6a-66b3593854f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019b6cdc-8e2c-73b6-89cc-f897861de118" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019b6cdc-8e2c-7851-bb6a-66b3593854f8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/TaxReceivableAgreementDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#TaxReceivableAgreementDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/TaxReceivableAgreementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_019d1a9f-b5c8-77ec-b8f1-a2646c1d73fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_019d1a9f-b5c8-77ec-b8f1-a2646c1d73fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d1a9f-d408-7566-996b-bd4b1140b609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceByDeferredTaxAssetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_019d1a9f-b5c8-77ec-b8f1-a2646c1d73fd" xlink:to="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d1a9f-d408-7566-996b-bd4b1140b609" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_019d1a9f-d408-7566-996b-bd4b1140b609_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d1a9f-d408-7566-996b-bd4b1140b609" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_019d1a9f-d408-7566-996b-bd4b1140b609_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_019d1a9f-d408-773e-8455-095c2944b47e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d1a9f-d408-7566-996b-bd4b1140b609" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_019d1a9f-d408-773e-8455-095c2944b47e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableLiabilityAgreementMember_019d2288-ee03-7fca-85f3-bccacf49c001" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableLiabilityAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetDomain_019d1a9f-d408-773e-8455-095c2944b47e" xlink:to="loc_lgn_TaxReceivableLiabilityAgreementMember_019d2288-ee03-7fca-85f3-bccacf49c001" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019d2462-f055-73dd-80de-8d1a5e36e3b8" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsOwed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsOwed_019d2462-f055-73dd-80de-8d1a5e36e3b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019d2462-f055-7cc4-9e40-695e26ef9997" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementCashTaxSavingsRetained"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_TaxReceivableAgreementCashTaxSavingsRetained_019d2462-f055-7cc4-9e40-695e26ef9997" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementLiabilityNoncurrent_019d2462-f055-7915-8ab5-3c7ee27eccf1" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_TaxReceivableAgreementLiabilityNoncurrent_019d2462-f055-7915-8ab5-3c7ee27eccf1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementLiabilityIncreaseDecrease_019d2634-7f57-7838-ae32-babb34772be7" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementLiabilityIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_TaxReceivableAgreementLiabilityIncreaseDecrease_019d2634-7f57-7838-ae32-babb34772be7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_DeferredTaxAssetsTaxReceivableAgreementLiability_019d2462-f055-7ec4-8b2d-6e898c6b1466" xlink:href="lgn-20251231.xsd#lgn_DeferredTaxAssetsTaxReceivableAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_DeferredTaxAssetsTaxReceivableAgreementLiability_019d2462-f055-7ec4-8b2d-6e898c6b1466" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_019d253b-8805-73fd-bd6a-bfcde05b0daf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_019d253b-8805-73fd-bd6a-bfcde05b0daf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_IncreaseToTaxReceivableAgreementLiabilityExpense_019d2462-f055-73cd-b998-d75f3e2230f8" xlink:href="lgn-20251231.xsd#lgn_IncreaseToTaxReceivableAgreementLiabilityExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_IncreaseToTaxReceivableAgreementLiabilityExpense_019d2462-f055-73cd-b998-d75f3e2230f8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_TaxReceivableAgreementBasisSpreadOnVariableRatePercentage_019d2462-f055-7c75-adc8-53763fba11b9" xlink:href="lgn-20251231.xsd#lgn_TaxReceivableAgreementBasisSpreadOnVariableRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_lgn_TaxReceivableAgreementBasisSpreadOnVariableRatePercentage_019d2462-f055-7c75-adc8-53763fba11b9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_019d2462-f055-76bd-8e7a-c396a2381b89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019d1a9f-d408-7303-9d92-59dfa5f746fa" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_019d2462-f055-76bd-8e7a-c396a2381b89" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansMultiemployerPlanDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansMultiemployerPlanDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansMultiemployerPlanDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c81-d248-70e7-80c7-59d5c2cfa382" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c81-d248-7252-baeb-70ccb134f592" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c81-d248-70e7-80c7-59d5c2cfa382" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c81-d248-7252-baeb-70ccb134f592" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanNameAxis_019b8c82-2820-77b9-910b-73f4f6cae12c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c81-d248-7252-baeb-70ccb134f592" xlink:to="loc_us-gaap_RetirementPlanNameAxis_019b8c82-2820-77b9-910b-73f4f6cae12c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-77b9-910b-73f4f6cae12c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_019b8c82-2820-77b9-910b-73f4f6cae12c" xlink:to="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-77b9-910b-73f4f6cae12c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_019b8c82-2820-77b9-910b-73f4f6cae12c" xlink:to="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SheetMetalWorkersPensionPlanOfSouthernCAAZNVMember_019b8c82-6f58-77d7-84d0-f234d2e35988" xlink:href="lgn-20251231.xsd#lgn_SheetMetalWorkersPensionPlanOfSouthernCAAZNVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_SheetMetalWorkersPensionPlanOfSouthernCAAZNVMember_019b8c82-6f58-77d7-84d0-f234d2e35988" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ArizonaPipeTradesTrustFundMember_019b8c82-ab54-718d-abe9-841ea64bff37" xlink:href="lgn-20251231.xsd#lgn_ArizonaPipeTradesTrustFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_ArizonaPipeTradesTrustFundMember_019b8c82-ab54-718d-abe9-841ea64bff37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_ElectricalWorkersLocal26PensionTrustFundMember_019b8c82-dd4b-7b63-9597-4feb6c7ccc69" xlink:href="lgn-20251231.xsd#lgn_ElectricalWorkersLocal26PensionTrustFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_ElectricalWorkersLocal26PensionTrustFundMember_019b8c82-dd4b-7b63-9597-4feb6c7ccc69" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_U.A.LocalNo.393PensionPlanMember_019b8c83-1044-74f5-8118-0716b33c0a2c" xlink:href="lgn-20251231.xsd#lgn_U.A.LocalNo.393PensionPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_U.A.LocalNo.393PensionPlanMember_019b8c83-1044-74f5-8118-0716b33c0a2c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_U.A.LocalNo.467DefinedBenefitPlanMember_019b8c83-4826-7f8d-8e7a-6c8d35f2b7c8" xlink:href="lgn-20251231.xsd#lgn_U.A.LocalNo.467DefinedBenefitPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_U.A.LocalNo.467DefinedBenefitPlanMember_019b8c83-4826-7f8d-8e7a-6c8d35f2b7c8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NorthernCAPipeTradesPensionPlanMember_019b8c83-7c32-7858-b555-a3306bf0cab3" xlink:href="lgn-20251231.xsd#lgn_NorthernCAPipeTradesPensionPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_NorthernCAPipeTradesPensionPlanMember_019b8c83-7c32-7858-b555-a3306bf0cab3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_PipeTradesServicesOfMNPensionPlanMember_019b8c83-ae1c-78f6-aa1e-9007eb0c4bc1" xlink:href="lgn-20251231.xsd#lgn_PipeTradesServicesOfMNPensionPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_PipeTradesServicesOfMNPensionPlanMember_019b8c83-ae1c-78f6-aa1e-9007eb0c4bc1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SheetMetalWorkersPensionPlanOfNorthernCAMember_019b8c83-e116-7039-9247-c080ab9cd4d6" xlink:href="lgn-20251231.xsd#lgn_SheetMetalWorkersPensionPlanOfNorthernCAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_SheetMetalWorkersPensionPlanOfNorthernCAMember_019b8c83-e116-7039-9247-c080ab9cd4d6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SouthernCAPipeTradesRetirementFundMember_019b8c84-0e29-779f-b446-e076ce7c1b9e" xlink:href="lgn-20251231.xsd#lgn_SouthernCAPipeTradesRetirementFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_SouthernCAPipeTradesRetirementFundMember_019b8c84-0e29-779f-b446-e076ce7c1b9e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_NationalElectricalBenefitFundMember_019b8c84-5164-723f-ab71-5e9daf83e34b" xlink:href="lgn-20251231.xsd#lgn_NationalElectricalBenefitFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_NationalElectricalBenefitFundMember_019b8c84-5164-723f-ab71-5e9daf83e34b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SheetMetalWorkersNationalPensionFundMember_019b8c85-d1f0-74b9-b1e8-9cac9a54f375" xlink:href="lgn-20251231.xsd#lgn_SheetMetalWorkersNationalPensionFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_SheetMetalWorkersNationalPensionFundMember_019b8c85-d1f0-74b9-b1e8-9cac9a54f375" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_UnitedAssociationNationalPensionFundMember_019b8c86-12f9-7d2a-b2fe-5ca9c135b1ab" xlink:href="lgn-20251231.xsd#lgn_UnitedAssociationNationalPensionFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_UnitedAssociationNationalPensionFundMember_019b8c86-12f9-7d2a-b2fe-5ca9c135b1ab" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_AllOtherPlansMember_019b8c86-4da3-78ad-bbcf-afec66ddfab8" xlink:href="lgn-20251231.xsd#lgn_AllOtherPlansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_019b8c82-2820-7574-b7e5-1b75a93a8bc2" xlink:to="loc_lgn_AllOtherPlansMember_019b8c86-4da3-78ad-bbcf-afec66ddfab8" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MultiemployerPlanEmployerContributionCost_019b8c81-d248-7488-8439-a16715172aad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MultiemployerPlanEmployerContributionCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c81-d248-70e7-80c7-59d5c2cfa382" xlink:to="loc_us-gaap_MultiemployerPlanEmployerContributionCost_019b8c81-d248-7488-8439-a16715172aad" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/UnionSponsoredPensionPlansandOtherEmployeeBenefitPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c8d-e71e-7496-941d-991b230ff569" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c8d-e71e-7496-941d-991b230ff569" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019b8c8e-3afa-7315-b5af-d582183c1d06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c8d-e71e-7496-941d-991b230ff569" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019b8c8e-3afa-7315-b5af-d582183c1d06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019b8c8e-3afa-7315-b5af-d582183c1d06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_019b8c8e-3afa-7315-b5af-d582183c1d06" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019b8c8e-3afa-7315-b5af-d582183c1d06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019b8c8e-3afa-7dce-b9f1-d4d109fbaa4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_019b8c8e-3afa-7315-b5af-d582183c1d06" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019b8c8e-3afa-7dce-b9f1-d4d109fbaa4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_HealthWelfareRetirementAndOtherBenefitsMember_019b8c91-1cae-757c-b153-62e931928dd9" xlink:href="lgn-20251231.xsd#lgn_HealthWelfareRetirementAndOtherBenefitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_019b8c8e-3afa-7dce-b9f1-d4d109fbaa4e" xlink:to="loc_lgn_HealthWelfareRetirementAndOtherBenefitsMember_019b8c91-1cae-757c-b153-62e931928dd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019b8c95-3508-7917-8b9e-cc0345d08b72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c8d-e71e-7496-941d-991b230ff569" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019b8c95-3508-7917-8b9e-cc0345d08b72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c95-3508-7917-8b9e-cc0345d08b72_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b8c95-3508-7917-8b9e-cc0345d08b72" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c95-3508-7917-8b9e-cc0345d08b72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c95-3508-723a-9f38-d65133f978bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019b8c95-3508-7917-8b9e-cc0345d08b72" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c95-3508-723a-9f38-d65133f978bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_Other2024AcquisitionMember_019b8c96-c69a-7619-aaae-bf8ffdbccca0" xlink:href="lgn-20251231.xsd#lgn_Other2024AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019b8c95-3508-723a-9f38-d65133f978bf" xlink:to="loc_lgn_Other2024AcquisitionMember_019b8c96-c69a-7619-aaae-bf8ffdbccca0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementAxis_019be1d9-c401-7633-ab42-933125ea302b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollectiveBargainingArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019b8c8d-e71e-7496-941d-991b230ff569" xlink:to="loc_us-gaap_CollectiveBargainingArrangementAxis_019be1d9-c401-7633-ab42-933125ea302b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementDomain_019be1d9-c401-7633-ab42-933125ea302b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollectiveBargainingArrangementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollectiveBargainingArrangementAxis_019be1d9-c401-7633-ab42-933125ea302b" xlink:to="loc_us-gaap_CollectiveBargainingArrangementDomain_019be1d9-c401-7633-ab42-933125ea302b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementDomain_019be1d9-c401-70d0-90e0-bb90592aac1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollectiveBargainingArrangementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollectiveBargainingArrangementAxis_019be1d9-c401-7633-ab42-933125ea302b" xlink:to="loc_us-gaap_CollectiveBargainingArrangementDomain_019be1d9-c401-70d0-90e0-bb90592aac1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_HealthWelfareRetirementAndOtherBenefitsMember_019be1da-8305-7b64-997a-72dccd6c2924" xlink:href="lgn-20251231.xsd#lgn_HealthWelfareRetirementAndOtherBenefitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollectiveBargainingArrangementDomain_019be1d9-c401-70d0-90e0-bb90592aac1b" xlink:to="loc_lgn_HealthWelfareRetirementAndOtherBenefitsMember_019be1da-8305-7b64-997a-72dccd6c2924" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MultiemployerPlanIncreaseInEmployerContributionBusinessCombinationAmount_019be1d1-3b54-7aea-994f-3bc2c93b5d78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MultiemployerPlanIncreaseInEmployerContributionBusinessCombinationAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:to="loc_us-gaap_MultiemployerPlanIncreaseInEmployerContributionBusinessCombinationAmount_019be1d1-3b54-7aea-994f-3bc2c93b5d78" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MultiemployerPlanEmployerContributionCost_019be1d8-a981-764a-af91-62d028f239a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MultiemployerPlanEmployerContributionCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:to="loc_us-gaap_MultiemployerPlanEmployerContributionCost_019be1d8-a981-764a-af91-62d028f239a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_019b8c8d-e71e-7cc9-b84e-5d868435c4ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_019b8c8d-e71e-7cc9-b84e-5d868435c4ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_019b8c99-8eb1-7912-b3fa-3586e771eda6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019b8c8d-e71e-77e7-a612-96d757c6f340" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_019b8c99-8eb1-7912-b3fa-3586e771eda6" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_019b6f04-8c7a-7a63-b198-a961e3bb4452" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_019b6f04-8c7a-7a63-b198-a961e3bb4452" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019d05c5-2b31-70f6-a4ec-9a222addc628" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_019b6f04-8c7a-7a63-b198-a961e3bb4452" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019d05c5-2b31-70f6-a4ec-9a222addc628" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-70f6-a4ec-9a222addc628_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019d05c5-2b31-70f6-a4ec-9a222addc628" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-70f6-a4ec-9a222addc628_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-7e31-b1d9-8924c173a55c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019d05c5-2b31-70f6-a4ec-9a222addc628" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-7e31-b1d9-8924c173a55c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_019d05c5-2b31-70d0-904f-fa57b75f56db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-7e31-b1d9-8924c173a55c" xlink:to="loc_us-gaap_DomesticCountryMember_019d05c5-2b31-70d0-904f-fa57b75f56db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_019d05c5-2b31-7ea7-b804-18a22e410b6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019d05c5-2b31-7e31-b1d9-8924c173a55c" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_019d05c5-2b31-7ea7-b804-18a22e410b6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d05c5-2b31-74b6-b6f9-fd465c65b432" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceByDeferredTaxAssetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_019b6f04-8c7a-7a63-b198-a961e3bb4452" xlink:to="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d05c5-2b31-74b6-b6f9-fd465c65b432" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_019d05c5-2b31-74b6-b6f9-fd465c65b432_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d05c5-2b31-74b6-b6f9-fd465c65b432" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_019d05c5-2b31-74b6-b6f9-fd465c65b432_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_019d05c5-2b31-793f-8d57-c920c774fe2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_019d05c5-2b31-74b6-b6f9-fd465c65b432" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_019d05c5-2b31-793f-8d57-c920c774fe2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InvestmentInLegenceHoldingsMember_019d0bca-7e4c-7f39-9e18-d60ef6dd1d4d" xlink:href="lgn-20251231.xsd#lgn_InvestmentInLegenceHoldingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetDomain_019d05c5-2b31-793f-8d57-c920c774fe2d" xlink:to="loc_lgn_InvestmentInLegenceHoldingsMember_019d0bca-7e4c-7f39-9e18-d60ef6dd1d4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019d05c5-5114-73b9-9f85-5b8684be749b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_019b6f04-8c7a-7a63-b198-a961e3bb4452" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019d05c5-5114-73b9-9f85-5b8684be749b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019d05c5-5114-73b9-9f85-5b8684be749b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019d05c5-5114-73b9-9f85-5b8684be749b" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019d05c5-5114-73b9-9f85-5b8684be749b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019d05c5-5114-7659-8188-03ddbd704d6e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019d05c5-5114-73b9-9f85-5b8684be749b" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019d05c5-5114-7659-8188-03ddbd704d6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019d05c5-5114-7c3e-ab39-efaa519b6ab1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019d05c5-5114-7659-8188-03ddbd704d6e" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019d05c5-5114-7c3e-ab39-efaa519b6ab1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d05c4-c5b7-70c1-906c-48208f50d37e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d05c4-c5b7-70c1-906c-48208f50d37e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InterestCarryforward_019d0bc6-e552-75f5-a831-75bd75439256" xlink:href="lgn-20251231.xsd#lgn_InterestCarryforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_lgn_InterestCarryforward_019d0bc6-e552-75f5-a831-75bd75439256" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_019d05c5-2b31-7a3b-9770-7792961fa119" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_OperatingLossCarryforwards_019d05c5-2b31-7a3b-9770-7792961fa119" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_OperatingLossCarryforwardsSubjectToEarlyExpiration_019d05c5-2b31-786b-b2a5-f56815be14f8" xlink:href="lgn-20251231.xsd#lgn_OperatingLossCarryforwardsSubjectToEarlyExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_lgn_OperatingLossCarryforwardsSubjectToEarlyExpiration_019d05c5-2b31-786b-b2a5-f56815be14f8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_019d05c5-2b31-723c-9100-fe5a2ec49166" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_019d05c5-2b31-723c-9100-fe5a2ec49166" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_019d05c5-5114-70cc-98e5-a924baabccf7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_019d05c5-5114-70cc-98e5-a924baabccf7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition_019d05c5-5114-7ca6-afef-e703bf0690f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition_019d05c5-5114-7ca6-afef-e703bf0690f0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019d05c5-5114-70e0-b5f4-b710c65b9918" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019d05c5-5114-70e0-b5f4-b710c65b9918" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_019d1d19-5cfc-7f8a-83f1-999a8c1d607c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019b6f04-8c7a-74a0-8acf-ee3167aa75f4" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_019d1d19-5cfc-7f8a-83f1-999a8c1d607c" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/IncomeTaxesScheduleofCashPaidforIncomeTaxesNetofRefundsDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#IncomeTaxesScheduleofCashPaidforIncomeTaxesNetofRefundsDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/IncomeTaxesScheduleofCashPaidforIncomeTaxesNetofRefundsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019cf547-d394-7bcf-8583-5a6a8f7edcf7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019cf547-d394-7bcf-8583-5a6a8f7edcf7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019cf547-d394-7335-acc1-3a48652007d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019cf547-d394-7bcf-8583-5a6a8f7edcf7" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019cf547-d394-7335-acc1-3a48652007d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019cf547-d394-7335-acc1-3a48652007d1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019cf547-d394-7335-acc1-3a48652007d1" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019cf547-d394-7335-acc1-3a48652007d1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019cf547-d394-7bbb-a6f2-44142ea1d080" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019cf547-d394-7335-acc1-3a48652007d1" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019cf547-d394-7bbb-a6f2-44142ea1d080" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_019d1bff-2515-7ddb-9ebe-8515d49b5abd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019cf547-d394-7bbb-a6f2-44142ea1d080" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_019d1bff-2515-7ddb-9ebe-8515d49b5abd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_CA_019cf548-8846-702e-8a90-c014db9f0150" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember_019d1bff-2515-7ddb-9ebe-8515d49b5abd" xlink:to="loc_stpr_CA_019cf548-8846-702e-8a90-c014db9f0150" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_PA_019cf548-c77f-748d-b570-68dc193e9de5" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_PA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember_019d1bff-2515-7ddb-9ebe-8515d49b5abd" xlink:to="loc_stpr_PA_019cf548-c77f-748d-b570-68dc193e9de5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalTaxJurisdictionOtherMember_019cf547-d394-7843-962b-464b0203af59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalTaxJurisdictionOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember_019d1bff-2515-7ddb-9ebe-8515d49b5abd" xlink:to="loc_us-gaap_StateAndLocalTaxJurisdictionOtherMember_019cf547-d394-7843-962b-464b0203af59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019cf547-d394-727c-a0a1-3d670908d5e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:to="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019cf547-d394-727c-a0a1-3d670908d5e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_019cf547-d394-79d4-9cc5-0ef2563de46f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:to="loc_us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_019cf547-d394-79d4-9cc5-0ef2563de46f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019cf547-d394-75e6-bae4-4b39fcf6204b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidForeignAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:to="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019cf547-d394-75e6-bae4-4b39fcf6204b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_019cf547-d394-726f-8a93-a9d3a6344dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019cf547-d394-7d68-a61f-a162736d34f2" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_019cf547-d394-726f-8a93-a9d3a6344dc4" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/SegmentInformationScheduleofSegmentReportingInformationDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#SegmentInformationScheduleofSegmentReportingInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/SegmentInformationScheduleofSegmentReportingInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019b49a0-0df2-73e6-9008-6329df55515f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019b49a0-0df2-73e6-9008-6329df55515f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019b49a0-0df2-7c81-a2de-df1d0c606f08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019b49a0-0df2-73e6-9008-6329df55515f" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019b49a0-0df2-7c81-a2de-df1d0c606f08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b49a0-0df2-7c81-a2de-df1d0c606f08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b49a0-0df2-7c81-a2de-df1d0c606f08" xlink:to="loc_us-gaap_SegmentDomain_019b49a0-0df2-7c81-a2de-df1d0c606f08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019b49a0-0df2-7174-a8fd-6e6adfbbda55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019b49a0-0df2-7c81-a2de-df1d0c606f08" xlink:to="loc_us-gaap_SegmentDomain_019b49a0-0df2-7174-a8fd-6e6adfbbda55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_EngineeringConsultingMember_019b49a0-0df2-7c70-bc9b-913a8e84b4fd" xlink:href="lgn-20251231.xsd#lgn_EngineeringConsultingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b49a0-0df2-7174-a8fd-6e6adfbbda55" xlink:to="loc_lgn_EngineeringConsultingMember_019b49a0-0df2-7c70-bc9b-913a8e84b4fd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_InstallationMaintenanceMember_019b49a0-0df2-77bf-9a31-f10ae0ed6aa2" xlink:href="lgn-20251231.xsd#lgn_InstallationMaintenanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019b49a0-0df2-7174-a8fd-6e6adfbbda55" xlink:to="loc_lgn_InstallationMaintenanceMember_019b49a0-0df2-77bf-9a31-f10ae0ed6aa2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019b49a0-0df2-707f-a6fa-2fdae122fe92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_RevenuesAbstract_019b49a0-0df2-707f-a6fa-2fdae122fe92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b49a0-0df2-73cd-8784-5a03989903a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_019b49a0-0df2-707f-a6fa-2fdae122fe92" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019b49a0-0df2-73cd-8784-5a03989903a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019b49a0-0df2-7423-a3b9-4175b8eea0f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSoldAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019b49a0-0df2-7423-a3b9-4175b8eea0f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019b49a0-0df2-7a8e-8b5c-f6f439d9fb2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019b49a0-0df2-7423-a3b9-4175b8eea0f2" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019b49a0-0df2-7a8e-8b5c-f6f439d9fb2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfitAbstract_019b49a0-0df2-73d1-a70f-8ecf82c344ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfitAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_GrossProfitAbstract_019b49a0-0df2-73d1-a70f-8ecf82c344ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019b49a0-0df2-7a76-a680-23a3ce983ded" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GrossProfitAbstract_019b49a0-0df2-73d1-a70f-8ecf82c344ab" xlink:to="loc_us-gaap_GrossProfit_019b49a0-0df2-7a76-a680-23a3ce983ded" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019b49a0-0df2-7caf-bc3a-80055e398019" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019b49a0-0df2-7caf-bc3a-80055e398019" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019b49a0-0df2-74c0-8c90-124ef199e40a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_DepreciationAndAmortization_019b49a0-0df2-74c0-8c90-124ef199e40a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019b49a0-0df2-7b6b-9de8-c44bc0ed95e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019b49a0-0df2-7b6b-9de8-c44bc0ed95e3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019b49bf-8507-7e34-9de7-0dfb145d24cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019b49bf-8507-7e34-9de7-0dfb145d24cf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_019cf4da-9dc1-78cc-8d0e-052aacfe36ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_019cf4da-9dc1-78cc-8d0e-052aacfe36ae" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019b49bf-8507-7c03-9dd3-d62ac764d7f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019b49bf-8507-7c03-9dd3-d62ac764d7f3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d0a53-5663-76eb-9496-a4963d38ca3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019d0a53-5663-76eb-9496-a4963d38ca3a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019b49a0-0df2-74c8-b6bc-4988987c4599" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019b49a0-0df2-74c8-b6bc-4988987c4599" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019b49a0-0df2-7748-853b-54782dacc707" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019b49a0-0df2-7748-853b-54782dacc707" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019b49a0-0df2-74fa-bbd7-6e66bca4dc8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019b49a0-0df2-74fa-bbd7-6e66bca4dc8b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019cf4dc-1599-714d-b3e3-c63ceca4033e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019cf4dc-1599-714d-b3e3-c63ceca4033e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_LineOfCreditFacilityAmendmentFeeAmount_019b49a0-0df2-79b1-99d5-1bd8ac19799a" xlink:href="lgn-20251231.xsd#lgn_LineOfCreditFacilityAmendmentFeeAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_lgn_LineOfCreditFacilityAmendmentFeeAmount_019b49a0-0df2-79b1-99d5-1bd8ac19799a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019b49a0-0df2-7f0c-b5d8-978a6a2ef79c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019b49a0-0df2-7f0c-b5d8-978a6a2ef79c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019b49a0-0df2-785f-822d-ed990985098c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019b49a0-0df2-7a31-9181-b953ce028641" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019b49a0-0df2-785f-822d-ed990985098c" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wearelegence.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="lgn-20251231.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.wearelegence.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019caec9-9687-75be-b261-364bc57b5fc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019caec9-9687-75be-b261-364bc57b5fc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019caec9-9687-75be-b261-364bc57b5fc8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019caec9-9687-75be-b261-364bc57b5fc8" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019caec9-9687-75be-b261-364bc57b5fc8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019caec9-9687-7fe8-9169-05febf5fb388" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019caec9-9687-75be-b261-364bc57b5fc8" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019caec9-9687-7fe8-9169-05febf5fb388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceClaimsMember_019caec9-9687-724f-8519-89ea5695bf41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InsuranceClaimsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019caec9-9687-7fe8-9169-05febf5fb388" xlink:to="loc_us-gaap_InsuranceClaimsMember_019caec9-9687-724f-8519-89ea5695bf41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019caec9-9687-7042-bd27-014f557d732d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:to="loc_us-gaap_CreditFacilityAxis_019caec9-9687-7042-bd27-014f557d732d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019caec9-9687-7042-bd27-014f557d732d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019caec9-9687-7042-bd27-014f557d732d" xlink:to="loc_us-gaap_CreditFacilityDomain_019caec9-9687-7042-bd27-014f557d732d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019caec9-9687-7057-ac0b-f8f763e8f51e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019caec9-9687-7042-bd27-014f557d732d" xlink:to="loc_us-gaap_CreditFacilityDomain_019caec9-9687-7057-ac0b-f8f763e8f51e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019caec9-9687-7b6d-8c07-397cc000a8b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019caec9-9687-7057-ac0b-f8f763e8f51e" xlink:to="loc_us-gaap_LineOfCreditMember_019caec9-9687-7b6d-8c07-397cc000a8b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019caec9-9687-7824-b066-ff5df1fc6216" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:to="loc_us-gaap_DebtInstrumentAxis_019caec9-9687-7824-b066-ff5df1fc6216" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019caec9-9687-7824-b066-ff5df1fc6216_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019caec9-9687-7824-b066-ff5df1fc6216" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019caec9-9687-7824-b066-ff5df1fc6216_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019caec9-9687-7870-91e5-f2185c06ceb8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019caec9-9687-7824-b066-ff5df1fc6216" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019caec9-9687-7870-91e5-f2185c06ceb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember_019caec9-9687-7f5b-9852-5699a8beedcd" xlink:href="lgn-20251231.xsd#lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019caec9-9687-7870-91e5-f2185c06ceb8" xlink:to="loc_lgn_JefferiesFinanceLLCRevolvingLineOfCreditMember_019caec9-9687-7f5b-9852-5699a8beedcd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019caec9-9687-7b06-a12c-074f6993ed3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019b46ca-a6ea-77dc-9917-a40e0493ebd3" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019caec9-9687-7b06-a12c-074f6993ed3d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019caec9-9687-7b06-a12c-074f6993ed3d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019caec9-9687-7b06-a12c-074f6993ed3d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019caec9-9687-7b06-a12c-074f6993ed3d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019caec9-9687-7a19-931d-74c91ba54e43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019caec9-9687-7b06-a12c-074f6993ed3d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019caec9-9687-7a19-931d-74c91ba54e43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_019caec9-9687-721f-8d3a-d6c833106b25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019caec9-9687-7a19-931d-74c91ba54e43" xlink:to="loc_us-gaap_LetterOfCreditMember_019caec9-9687-721f-8d3a-d6c833106b25" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_019d0bcc-1284-793a-a7ed-bd14f63624ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_019d0bcc-1284-793a-a7ed-bd14f63624ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_019caec9-9687-7ee6-86d3-248b31d19e20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualCarryingValueCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_019caec9-9687-7ee6-86d3-248b31d19e20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SelfInsuranceThresholdForStopLossInsurance_019caec9-9687-795b-b838-6799c8e62979" xlink:href="lgn-20251231.xsd#lgn_SelfInsuranceThresholdForStopLossInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_lgn_SelfInsuranceThresholdForStopLossInsurance_019caec9-9687-795b-b838-6799c8e62979" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SelfInsuranceReserveCurrent_019caec9-9687-7dc9-8a3d-7a9f75f66d84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserveCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_SelfInsuranceReserveCurrent_019caec9-9687-7dc9-8a3d-7a9f75f66d84" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lgn_SuretyBondsOutstanding_019caec9-9687-73d5-8e05-2c677e47f1d8" xlink:href="lgn-20251231.xsd#lgn_SuretyBondsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_lgn_SuretyBondsOutstanding_019caec9-9687-73d5-8e05-2c677e47f1d8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019caec9-9687-7cb0-88f1-e13dc6af61a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019caec9-9687-7cb0-88f1-e13dc6af61a4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019caec9-9687-76bf-a42c-7e1023fe6e68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019b46ca-a6ea-7b32-98e9-b039e4a38fd9" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019caec9-9687-76bf-a42c-7e1023fe6e68" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:type="arc" order="41"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="32"/>
  </link:definitionLink>
</link:linkbase>
