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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019d2532-bfc0-722e-9ab6-bc14c5062743,g:9956348c-3922-4c8c-aaf9-3264642cbc1c-->
<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://ir.sunriserealtytrust.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="suns-20260331.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2532-c1f5-7ec6-80f7-4ac191a8166c" 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_019d2532-c1f5-73f8-9fa2-277ee66203d5" 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_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_StatementTable_019d2532-c1f5-73f8-9fa2-277ee66203d5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c1f5-79e3-83e1-05181c3e98ee" 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_019d2532-c1f5-73f8-9fa2-277ee66203d5" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c1f5-79e3-83e1-05181c3e98ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c1f5-79e3-83e1-05181c3e98ee_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_019d2532-c1f5-79e3-83e1-05181c3e98ee" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c1f5-79e3-83e1-05181c3e98ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c1f5-7a43-8260-bb9326eb29b3" 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_019d2532-c1f5-79e3-83e1-05181c3e98ee" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c1f5-7a43-8260-bb9326eb29b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019d2532-c1f5-7d52-a955-a05f388bd614" 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_019d2532-c1f5-7a43-8260-bb9326eb29b3" xlink:to="loc_us-gaap_NonrelatedPartyMember_019d2532-c1f5-7d52-a955-a05f388bd614" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2532-c1f5-72f3-9c94-c123395b7d46" 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_019d2532-c1f5-7a43-8260-bb9326eb29b3" xlink:to="loc_us-gaap_RelatedPartyMember_019d2532-c1f5-72f3-9c94-c123395b7d46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" 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_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss_019d2532-c1f5-71b3-b534-d60ea02a6a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss_019d2532-c1f5-71b3-b534-d60ea02a6a8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f5-7bb3-a327-18c297c6878b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f5-7bb3-a327-18c297c6878b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019d2532-c1f5-749b-863a-13a6df025e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_NotesReceivableNet_019d2532-c1f5-749b-863a-13a6df025e7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d2532-c1f5-7f70-8272-ef12c389d188" 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_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d2532-c1f5-7f70-8272-ef12c389d188" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestReceivable_019d2532-c1f5-7d1a-90a9-a7299faf4fce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_InterestReceivable_019d2532-c1f5-7d1a-90a9-a7299faf4fce" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019d622f-ac0c-7d42-b0f5-671c5b210cb3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019d622f-ac0c-7d42-b0f5-671c5b210cb3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssets_019d2532-c1f5-769c-b1a4-fa9f6d16f10c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssets_019d2532-c1f5-769c-b1a4-fa9f6d16f10c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d2532-c1f5-7fa6-98ef-27a8405aa9ff" 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_019d2532-c1f5-752a-8b0c-8cd64904f44b" xlink:to="loc_us-gaap_Assets_019d2532-c1f5-7fa6-98ef-27a8405aa9ff" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPayableCurrentAndNoncurrent_019d2532-c1f5-7821-b10f-aee6bddace03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_InterestPayableCurrentAndNoncurrent_019d2532-c1f5-7821-b10f-aee6bddace03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_019d2532-c1f5-7f85-b797-cb97e6f33756" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_019d2532-c1f5-7f85-b797-cb97e6f33756" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss_019d2532-c1f5-7e43-86e6-b1c6e6a2da13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss_019d2532-c1f5-7e43-86e6-b1c6e6a2da13" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeePayable_019d2532-c1f5-79e2-b327-6e71b9064448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_ManagementFeePayable_019d2532-c1f5-79e2-b327-6e71b9064448" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_AccruedDirectAdministrativeExpenses_019d2532-c1f5-7e97-944b-7b9368a65855" xlink:href="suns-20260331.xsd#suns_AccruedDirectAdministrativeExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_suns_AccruedDirectAdministrativeExpenses_019d2532-c1f5-7e97-944b-7b9368a65855" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_019d2532-c1f5-71b2-ae7b-a235336ad88a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_019d2532-c1f5-71b2-ae7b-a235336ad88a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019d2532-c1f5-785a-b63f-e69534f017f1" 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_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_LineOfCredit_019d2532-c1f5-785a-b63f-e69534f017f1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d2532-c1f5-756e-9388-f3d490273734" 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_LiabilitiesAbstract_019d2532-c1f5-7490-8502-bd507e9aa3f6" xlink:to="loc_us-gaap_Liabilities_019d2532-c1f5-756e-9388-f3d490273734" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019d2532-c1f5-79e2-bc1a-223579cfbe2b" 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_StatementLineItems_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019d2532-c1f5-79e2-bc1a-223579cfbe2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_019d2532-c1f5-7c3a-884f-992b27621aca" 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_StatementLineItems_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_StockholdersEquityAbstract_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019d2532-c1f5-78f8-9f2b-82b4dc305950" 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_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:to="loc_us-gaap_PreferredStockValue_019d2532-c1f5-78f8-9f2b-82b4dc305950" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019d2532-c1f5-74a5-ae01-7885163d6654" 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_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:to="loc_us-gaap_CommonStockValue_019d2532-c1f5-74a5-ae01-7885163d6654" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019d2532-c1f5-7ff9-822e-c3c366b258ac" 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_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019d2532-c1f5-7ff9-822e-c3c366b258ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d2532-c1f5-7d05-9df3-f6f65acb32bf" 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_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d2532-c1f5-7d05-9df3-f6f65acb32bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d2532-c1f5-7522-b6ce-9093fda4d459" 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_StockholdersEquityAbstract_019d2532-c1f5-7c3a-884f-992b27621aca" xlink:to="loc_us-gaap_StockholdersEquity_019d2532-c1f5-7522-b6ce-9093fda4d459" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d2532-c1f5-7e63-80b0-898763c363bd" 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_StatementLineItems_019d2532-c1f5-7ec6-80f7-4ac191a8166c" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d2532-c1f5-7e63-80b0-898763c363bd" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYunaudited" xlink:type="simple" xlink:href="suns-20260331.xsd#CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYunaudited"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019d2532-c1f5-7726-9f03-c7fe4750c410" 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_019d2532-c1f5-72cd-b1a3-c3ac93a6602f" 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_019d2532-c1f5-7726-9f03-c7fe4750c410" xlink:to="loc_us-gaap_StatementTable_019d2532-c1f5-72cd-b1a3-c3ac93a6602f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019d2532-c1f5-7682-9396-228c7cba2e29" 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_019d2532-c1f5-72cd-b1a3-c3ac93a6602f" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019d2532-c1f5-7682-9396-228c7cba2e29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019d2532-c1f5-7682-9396-228c7cba2e29_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_019d2532-c1f5-7682-9396-228c7cba2e29" xlink:to="loc_us-gaap_EquityComponentDomain_019d2532-c1f5-7682-9396-228c7cba2e29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019d2532-c1f5-7307-a5c9-18254e90c462" 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_019d2532-c1f5-7682-9396-228c7cba2e29" xlink:to="loc_us-gaap_EquityComponentDomain_019d2532-c1f5-7307-a5c9-18254e90c462" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019d2532-c1f5-7f8c-8f54-92d2dc4f59d6" 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_019d2532-c1f5-7307-a5c9-18254e90c462" xlink:to="loc_us-gaap_CommonStockMember_019d2532-c1f5-7f8c-8f54-92d2dc4f59d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019d2532-c1f5-74f4-b0ac-529977fa7ca4" 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_EquityComponentDomain_019d2532-c1f5-7307-a5c9-18254e90c462" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019d2532-c1f5-74f4-b0ac-529977fa7ca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019d2532-c1f5-73d6-8a75-8e59b1e51dcc" 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_EquityComponentDomain_019d2532-c1f5-7307-a5c9-18254e90c462" xlink:to="loc_us-gaap_RetainedEarningsMember_019d2532-c1f5-73d6-8a75-8e59b1e51dcc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" 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_019d2532-c1f5-7726-9f03-c7fe4750c410" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d2532-c1f5-715a-ab4e-3f26f56cb967" 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_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_StockholdersEquity_019d2532-c1f5-715a-ab4e-3f26f56cb967" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019d2532-c1f5-7978-9555-f5dd992b2359" 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_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019d2532-c1f5-7978-9555-f5dd992b2359" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SharesIssuedSharesShareBasedPaymentArrangementNettedAfterForfeiture_019d2532-c1f5-7e43-8c92-d4b5804d663d" xlink:href="suns-20260331.xsd#suns_SharesIssuedSharesShareBasedPaymentArrangementNettedAfterForfeiture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_suns_SharesIssuedSharesShareBasedPaymentArrangementNettedAfterForfeiture_019d2532-c1f5-7e43-8c92-d4b5804d663d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SharesGrantedValueShareBasedPaymentArrangementNettedAfterForfeiture_019d2532-c1f5-7f42-8b40-d890de60e274" xlink:href="suns-20260331.xsd#suns_SharesGrantedValueShareBasedPaymentArrangementNettedAfterForfeiture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_suns_SharesGrantedValueShareBasedPaymentArrangementNettedAfterForfeiture_019d2532-c1f5-7f42-8b40-d890de60e274" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019d2532-c1f5-7617-9a1d-489bfdd10f8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_DividendsCommonStockCash_019d2532-c1f5-7617-9a1d-489bfdd10f8d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019d6237-c414-7d9a-902a-023305b66b1c" 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_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019d6237-c414-7d9a-902a-023305b66b1c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019d6237-c414-7333-8631-a09bc6fd0538" 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_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019d6237-c414-7333-8631-a09bc6fd0538" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d2532-c1f5-7175-88f5-cd53899a3eaa" 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_IncreaseDecreaseInStockholdersEquityRollForward_019d2532-c1f5-7d34-a2b9-20a477c21328" xlink:to="loc_us-gaap_NetIncomeLoss_019d2532-c1f5-7175-88f5-cd53899a3eaa" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d2532-c1f5-7831-973e-470cba404630" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019d2532-c1f5-7591-ab07-65652ee374f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUENarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#LOANSHELDFORINVESTMENTATCARRYINGVALUENarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUENarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d629d-013a-7b11-a06d-717ac90818ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d629d-013a-7b11-a06d-717ac90818ef" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019d629d-013a-7732-b615-0544013b1e54" 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_LoansAndLeasesReceivableDisclosureTable_019d629d-013a-7b11-a06d-717ac90818ef" xlink:to="loc_us-gaap_VariableRateAxis_019d629d-013a-7732-b615-0544013b1e54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d629d-013a-7732-b615-0544013b1e54_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_019d629d-013a-7732-b615-0544013b1e54" xlink:to="loc_us-gaap_VariableRateDomain_019d629d-013a-7732-b615-0544013b1e54_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d629d-013a-7b3f-b1c5-b094f2311354" 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_019d629d-013a-7732-b615-0544013b1e54" xlink:to="loc_us-gaap_VariableRateDomain_019d629d-013a-7b3f-b1c5-b094f2311354" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d629d-013a-750e-9808-26b514adade2" 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_019d629d-013a-7b3f-b1c5-b094f2311354" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d629d-013a-750e-9808-26b514adade2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrimeRateMember_019d629d-013a-70d9-a1fc-5f5f089b81b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d629d-013a-7b3f-b1c5-b094f2311354" xlink:to="loc_us-gaap_PrimeRateMember_019d629d-013a-70d9-a1fc-5f5f089b81b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_NumberOfLoansHeldForInvestments_019d629d-013a-7bd9-a689-ae62e909e579" xlink:href="suns-20260331.xsd#suns_NumberOfLoansHeldForInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_NumberOfLoansHeldForInvestments_019d629d-013a-7bd9-a689-ae62e909e579" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentAtCarryingValueAggregateCommitments_019d629d-013a-7a0f-af70-b4c0afdafb85" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentAtCarryingValueAggregateCommitments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_LoansHeldForInvestmentAtCarryingValueAggregateCommitments_019d629d-013a-7a0f-af70-b4c0afdafb85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d629d-013a-7adb-a667-a20e65439746" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d629d-013a-7adb-a667-a20e65439746" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentAtCarryingValueOutstandingPrincipalNewFundings_019d629d-013a-772e-a35f-8649f32067e4" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentAtCarryingValueOutstandingPrincipalNewFundings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_LoansHeldForInvestmentAtCarryingValueOutstandingPrincipalNewFundings_019d629d-013a-772e-a35f-8649f32067e4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ReceivableWithImputedInterestLoanRepaymentsAndAmortizationPayments_019d629d-013a-7299-969f-8653d55418d4" xlink:href="suns-20260331.xsd#suns_ReceivableWithImputedInterestLoanRepaymentsAndAmortizationPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_ReceivableWithImputedInterestLoanRepaymentsAndAmortizationPayments_019d629d-013a-7299-969f-8653d55418d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_PercentageOfLoansHeldWithFloatingInterestRates_019d629d-013a-7f1b-a90d-7c31048b40a2" xlink:href="suns-20260331.xsd#suns_PercentageOfLoansHeldWithFloatingInterestRates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_PercentageOfLoansHeldWithFloatingInterestRates_019d629d-013a-7f1b-a90d-7c31048b40a2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentQuotedInterestRate_019d629d-013a-749a-ba7d-83a4f2887c7c" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentQuotedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_LoansHeldForInvestmentQuotedInterestRate_019d629d-013a-749a-ba7d-83a4f2887c7c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentInterestRateFloor_019d629d-013a-7911-b866-f5ff9bed4533" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentInterestRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_LoansHeldForInvestmentInterestRateFloor_019d629d-013a-7911-b866-f5ff9bed4533" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_NumberOfLoansOnNonAccrualStatusCarryingValue_019d629d-26cf-766a-a8bd-265b5267e8f5" xlink:href="suns-20260331.xsd#suns_NumberOfLoansOnNonAccrualStatusCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_NumberOfLoansOnNonAccrualStatusCarryingValue_019d629d-26cf-766a-a8bd-265b5267e8f5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_NonCashInvestmentInUnconsolidatedRealEstateJointVenture_019e060d-751c-739f-92ed-9f9cbf38f5aa" xlink:href="suns-20260331.xsd#suns_NonCashInvestmentInUnconsolidatedRealEstateJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldMovementScheduleLineItems_019d629d-013a-7418-9987-510aecaad80e" xlink:to="loc_suns_NonCashInvestmentInUnconsolidatedRealEstateJointVenture_019e060d-751c-739f-92ed-9f9cbf38f5aa" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValueDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValueDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-7e02-bf85-c583bf692ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:to="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-7e02-bf85-c583bf692ad1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7d88-bbbe-850271c151f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-7e02-bf85-c583bf692ad1" xlink:to="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7d88-bbbe-850271c151f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-7d88-bbbe-850271c151f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7d88-bbbe-850271c151f2" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-7d88-bbbe-850271c151f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-78c9-bc65-c55c8c1edecb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7d88-bbbe-850271c151f2" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-78c9-bc65-c55c8c1edecb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorLoansMember_019d2532-c1f5-776e-9ab5-0a73305a3829" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-78c9-bc65-c55c8c1edecb" xlink:to="loc_us-gaap_SeniorLoansMember_019d2532-c1f5-776e-9ab5-0a73305a3829" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebtMember_019d2532-c1f5-7633-869b-e3f681b6160d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-78c9-bc65-c55c8c1edecb" xlink:to="loc_us-gaap_SubordinatedDebtMember_019d2532-c1f5-7633-869b-e3f681b6160d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d2532-c1f5-70ac-9937-afcade4df7d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:to="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d2532-c1f5-70ac-9937-afcade4df7d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestDiscount_019d2532-c1f5-7164-b0e6-b763a9e08b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:to="loc_us-gaap_ReceivableWithImputedInterestDiscount_019d2532-c1f5-7164-b0e6-b763a9e08b2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019d2532-c1f5-7610-8123-3d117f385039" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestNetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:to="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019d2532-c1f5-7610-8123-3d117f385039" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentWeightedAverageRemainingLife_019d2532-c1f5-72db-b60e-b1428fb3b90d" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentWeightedAverageRemainingLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-7019-b512-a5c4b2cda9a6" xlink:to="loc_suns_LoansHeldForInvestmentWeightedAverageRemainingLife_019d2532-c1f5-72db-b60e-b1428fb3b90d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValuePortfolioDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValuePortfolioDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/LOANSHELDFORINVESTMENTATCARRYINGVALUEScheduleofLoansHeldatCarryingValuePortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-757e-b346-f975f63c0a13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-757e-b346-f975f63c0a13" xlink:to="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis_019d2532-c1f5-75f1-a368-cefad5b2ea4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis_019d2532-c1f5-75f1-a368-cefad5b2ea4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-75f1-a368-cefad5b2ea4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis_019d2532-c1f5-75f1-a368-cefad5b2ea4a" xlink:to="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-75f1-a368-cefad5b2ea4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis_019d2532-c1f5-75f1-a368-cefad5b2ea4a" xlink:to="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanAustinTXMember_019d2532-c1f5-704c-b31f-12b6552615c0" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanAustinTXMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanAustinTXMember_019d2532-c1f5-704c-b31f-12b6552615c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLMember_019d2532-c1f5-7b3c-a7b1-0e934ffd443b" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLMember_019d2532-c1f5-7b3c-a7b1-0e934ffd443b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLIIMember_019d2532-c1f5-7b1e-b0a7-89d06df9c82e" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLIIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanPalmBeachGardensFLIIMember_019d2532-c1f5-7b1e-b0a7-89d06df9c82e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanFortLauderdaleFLMember_019d2532-c1f5-72d4-9f3f-05b7c7daf12e" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanFortLauderdaleFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanFortLauderdaleFLMember_019d2532-c1f5-72d4-9f3f-05b7c7daf12e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_MixedUseSeniorMortgageLoanAustinTXMember_019d2532-c1f5-7b0e-abb6-def7ef7e4ece" xlink:href="suns-20260331.xsd#suns_MixedUseSeniorMortgageLoanAustinTXMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_MixedUseSeniorMortgageLoanAustinTXMember_019d2532-c1f5-7b0e-abb6-def7ef7e4ece" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanAventuraFLMember_019d2532-c1f5-79b5-bbc6-ca45109fd973" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanAventuraFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanAventuraFLMember_019d2532-c1f5-79b5-bbc6-ca45109fd973" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_MixedUseSeniorMortgageLoanNewOrleansLAMember_019d2532-c1f5-7b6f-b711-32daedf838e0" xlink:href="suns-20260331.xsd#suns_MixedUseSeniorMortgageLoanNewOrleansLAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_MixedUseSeniorMortgageLoanNewOrleansLAMember_019d2532-c1f5-7b6f-b711-32daedf838e0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanParkCityUTMember_019d2532-c1f5-7a2b-9725-499d166a84b1" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanParkCityUTMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanParkCityUTMember_019d2532-c1f5-7a2b-9725-499d166a84b1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSeniorMortgageLoanMiamiFLMember_019d2532-c1f5-7ecf-83d9-a2534835a013" xlink:href="suns-20260331.xsd#suns_ResidentialUseSeniorMortgageLoanMiamiFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSeniorMortgageLoanMiamiFLMember_019d2532-c1f5-7ecf-83d9-a2534835a013" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_IndustrialUseSeniorMortgageLoanDoralFLMember_019d2532-c1f5-77a5-adba-67ca65ae3f86" xlink:href="suns-20260331.xsd#suns_IndustrialUseSeniorMortgageLoanDoralFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_IndustrialUseSeniorMortgageLoanDoralFLMember_019d2532-c1f5-77a5-adba-67ca65ae3f86" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_IndustrialUseSeniorMortgageLoanWestPalmBeachFLMember_019d2532-c1f5-7a9d-b7c6-509468d1f2bd" xlink:href="suns-20260331.xsd#suns_IndustrialUseSeniorMortgageLoanWestPalmBeachFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_IndustrialUseSeniorMortgageLoanWestPalmBeachFLMember_019d2532-c1f5-7a9d-b7c6-509468d1f2bd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_MixedUseSeniorMortgageLoanHoustonTXMember_019d2532-c1f5-7726-9283-eae520d1808d" xlink:href="suns-20260331.xsd#suns_MixedUseSeniorMortgageLoanHoustonTXMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_MixedUseSeniorMortgageLoanHoustonTXMember_019d2532-c1f5-7726-9283-eae520d1808d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSubordinateDebtMiamiFLMember_019d2532-c1f5-7b4e-a747-952456c6a2a2" xlink:href="suns-20260331.xsd#suns_ResidentialUseSubordinateDebtMiamiFLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSubordinateDebtMiamiFLMember_019d2532-c1f5-7b4e-a747-952456c6a2a2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialUseSubordinateDebtMiamiFLIIMember_019d2532-c1f5-7810-a1e1-25165cd2c6d6" xlink:href="suns-20260331.xsd#suns_ResidentialUseSubordinateDebtMiamiFLIIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_ResidentialUseSubordinateDebtMiamiFLIIMember_019d2532-c1f5-7810-a1e1-25165cd2c6d6" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_MixedUseSubordinateDebtMember_019dc25f-6825-7847-8566-1ac2a0748302" xlink:href="suns-20260331.xsd#suns_MixedUseSubordinateDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfFinancingReceivableTypeOfBorrowerDomain_019d2532-c1f5-76cc-94f9-cc585bc37609" xlink:to="loc_suns_MixedUseSubordinateDebtMember_019dc25f-6825-7847-8566-1ac2a0748302" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019d2532-c1f5-73ad-b2b2-b49f5af04dcd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_srt_StatementGeographicalAxis_019d2532-c1f5-73ad-b2b2-b49f5af04dcd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-73ad-b2b2-b49f5af04dcd_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019d2532-c1f5-73ad-b2b2-b49f5af04dcd" xlink:to="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-73ad-b2b2-b49f5af04dcd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019d2532-c1f5-73ad-b2b2-b49f5af04dcd" xlink:to="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_TX_019d2532-c1f5-7c62-bdd6-487ca885ce40" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_TX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:to="loc_stpr_TX_019d2532-c1f5-7c62-bdd6-487ca885ce40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_FL_019d2532-c1f5-7fd1-9005-d8cecbb62b4a" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_FL"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:to="loc_stpr_FL_019d2532-c1f5-7fd1-9005-d8cecbb62b4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_LA_019d2532-c1f5-7630-8bcd-8ba911f6f95e" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_LA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:to="loc_stpr_LA_019d2532-c1f5-7630-8bcd-8ba911f6f95e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_UT_019d2532-c1f5-7cb0-bc5d-93ea486e2663" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_UT"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019d2532-c1f5-7b38-a50d-79c33bdf84df" xlink:to="loc_stpr_UT_019d2532-c1f5-7cb0-bc5d-93ea486e2663" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019d2532-c1f5-75fb-9e24-51531d75ffe5" 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_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_us-gaap_VariableRateAxis_019d2532-c1f5-75fb-9e24-51531d75ffe5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d2532-c1f5-75fb-9e24-51531d75ffe5_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_019d2532-c1f5-75fb-9e24-51531d75ffe5" xlink:to="loc_us-gaap_VariableRateDomain_019d2532-c1f5-75fb-9e24-51531d75ffe5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d2532-c1f5-7481-9b74-b2ed9af50fef" 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_019d2532-c1f5-75fb-9e24-51531d75ffe5" xlink:to="loc_us-gaap_VariableRateDomain_019d2532-c1f5-7481-9b74-b2ed9af50fef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019d2532-c1f5-70ae-ad38-f9a882511b28" 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_019d2532-c1f5-7481-9b74-b2ed9af50fef" xlink:to="loc_us-gaap_BaseRateMember_019d2532-c1f5-70ae-ad38-f9a882511b28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d2532-c1f5-7e3a-9e9b-17688edc93c6" 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_019d2532-c1f5-7481-9b74-b2ed9af50fef" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d2532-c1f5-7e3a-9e9b-17688edc93c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrimeRateMember_019d2532-c1f5-7812-b7f8-92272523c3a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d2532-c1f5-7481-9b74-b2ed9af50fef" xlink:to="loc_us-gaap_PrimeRateMember_019d2532-c1f5-7812-b7f8-92272523c3a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_PaymentInKindPIKInterestRateMember_019d2532-c1f5-7ebb-84b4-1fe32640d8b2" xlink:href="suns-20260331.xsd#suns_PaymentInKindPIKInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019d2532-c1f5-7481-9b74-b2ed9af50fef" xlink:to="loc_suns_PaymentInKindPIKInterestRateMember_019d2532-c1f5-7ebb-84b4-1fe32640d8b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d2532-c1f5-7294-8636-b4300014c633" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d2532-c1f5-7294-8636-b4300014c633" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7294-8636-b4300014c633_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d2532-c1f5-7294-8636-b4300014c633" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7294-8636-b4300014c633_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d2532-c1f5-7294-8636-b4300014c633" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialMember_019d2532-c1f5-7af9-beed-28a890f3974b" xlink:href="suns-20260331.xsd#suns_ResidentialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:to="loc_suns_ResidentialMember_019d2532-c1f5-7af9-beed-28a890f3974b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_HospitalityMember_019d2532-c1f5-7b3f-a216-0355951c3a4a" xlink:href="suns-20260331.xsd#suns_HospitalityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:to="loc_suns_HospitalityMember_019d2532-c1f5-7b3f-a216-0355951c3a4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_NetLeasedTenantMember_019d2532-c1f5-72bc-96d2-5481d2fe18b9" xlink:href="suns-20260331.xsd#suns_NetLeasedTenantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:to="loc_suns_NetLeasedTenantMember_019d2532-c1f5-72bc-96d2-5481d2fe18b9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_IndustrialPropertyMember_019d2532-c1f5-7453-a9e3-86d7c601f09c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_IndustrialPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:to="loc_srt_IndustrialPropertyMember_019d2532-c1f5-7453-a9e3-86d7c601f09c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_MixedUseMember_019d2532-c1f5-79da-a5cf-2c48da19d33c" xlink:href="suns-20260331.xsd#suns_MixedUseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d2532-c1f5-7ed1-8bca-1da8674aa7d2" xlink:to="loc_suns_MixedUseMember_019d2532-c1f5-79da-a5cf-2c48da19d33c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7a6d-9293-a24ae64285a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7a6d-9293-a24ae64285a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-7a6d-9293-a24ae64285a0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7a6d-9293-a24ae64285a0" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-7a6d-9293-a24ae64285a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-73cb-8793-e1d15536ae26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019d2532-c1f5-7a6d-9293-a24ae64285a0" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-73cb-8793-e1d15536ae26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorLoansMember_019d2532-c1f5-7cf6-aa16-c3e46d47fa18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-73cb-8793-e1d15536ae26" xlink:to="loc_us-gaap_SeniorLoansMember_019d2532-c1f5-7cf6-aa16-c3e46d47fa18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebtMember_019d2532-c1f5-7429-9530-525988413630" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019d2532-c1f5-73cb-8793-e1d15536ae26" xlink:to="loc_us-gaap_SubordinatedDebtMember_019d2532-c1f5-7429-9530-525988413630" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d2532-c1f5-7647-b4b8-a65af95f8a9a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureTable_019d2532-c1f5-704f-8876-6c9235bffbe9" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d2532-c1f5-7647-b4b8-a65af95f8a9a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-7647-b4b8-a65af95f8a9a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d2532-c1f5-7647-b4b8-a65af95f8a9a" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-7647-b4b8-a65af95f8a9a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-76c4-91ae-64dfb7c805f9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d2532-c1f5-7647-b4b8-a65af95f8a9a" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-76c4-91ae-64dfb7c805f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ANotesMember_019d2532-c1f5-7747-8be7-8cda01afde48" xlink:href="suns-20260331.xsd#suns_ANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-76c4-91ae-64dfb7c805f9" xlink:to="loc_suns_ANotesMember_019d2532-c1f5-7747-8be7-8cda01afde48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_BNotesMember_019d2532-c1f5-73a6-bfd6-b38b96df3958" xlink:href="suns-20260331.xsd#suns_BNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019d2532-c1f5-76c4-91ae-64dfb7c805f9" xlink:to="loc_suns_BNotesMember_019d2532-c1f5-73a6-bfd6-b38b96df3958" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:href="suns-20260331.xsd#suns_LoansHeldAtInvestmentCarryingAmountAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableDisclosureLineItems_019d2532-c1f5-757e-b346-f975f63c0a13" xlink:to="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d2532-c1f5-7472-b584-fe0458acd5e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:to="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019d2532-c1f5-7472-b584-fe0458acd5e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestDiscount_019d2532-c1f5-7588-9c5c-bc16a5f0d15a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:to="loc_us-gaap_ReceivableWithImputedInterestDiscount_019d2532-c1f5-7588-9c5c-bc16a5f0d15a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestPremium_019d2532-c1f5-78dc-8a81-83405c478f44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:to="loc_us-gaap_ReceivableWithImputedInterestPremium_019d2532-c1f5-78dc-8a81-83405c478f44" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019d2532-c1f5-73ed-a576-bb9324deb1d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestNetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:to="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019d2532-c1f5-73ed-a576-bb9324deb1d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate_019d2532-c1f5-7bfa-a55a-f34d5691c170" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_suns_LoansHeldAtInvestmentCarryingAmountAbstract_019d2532-c1f5-714c-a92d-8b960ab7b201" xlink:to="loc_us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate_019d2532-c1f5-7bfa-a55a-f34d5691c170" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESNarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#CURRENTEXPECTEDCREDITLOSSESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f5-7920-8bca-0327585c6353" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f5-7920-8bca-0327585c6353" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-7920-8bca-0327585c6353_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f5-7920-8bca-0327585c6353" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-7920-8bca-0327585c6353_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-71a1-8def-ca8bfbaf0ade" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f5-7920-8bca-0327585c6353" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-71a1-8def-ca8bfbaf0ade" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_FundedLoanCommitmentMember_019d2532-c1f5-77bf-8f2f-761ba8e236dd" xlink:href="suns-20260331.xsd#suns_FundedLoanCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-71a1-8def-ca8bfbaf0ade" xlink:to="loc_suns_FundedLoanCommitmentMember_019d2532-c1f5-77bf-8f2f-761ba8e236dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnfundedLoanCommitmentMember_019d2532-c1f5-7610-887b-29a7b4b0ba63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnfundedLoanCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f5-71a1-8def-ca8bfbaf0ade" xlink:to="loc_us-gaap_UnfundedLoanCommitmentMember_019d2532-c1f5-7610-887b-29a7b4b0ba63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f5-7b69-b036-f2623dc2c4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f5-7b69-b036-f2623dc2c4e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f5-7b69-b036-f2623dc2c4e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f5-7b69-b036-f2623dc2c4e0" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f5-7b69-b036-f2623dc2c4e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f5-7354-89e0-e37012a5c8ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f5-7b69-b036-f2623dc2c4e0" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f5-7354-89e0-e37012a5c8ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_CurrentExpectedCreditLossesReserveMember_019d2532-c1f5-7afc-a0eb-3ef3ff0524b3" xlink:href="suns-20260331.xsd#suns_CurrentExpectedCreditLossesReserveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f5-7354-89e0-e37012a5c8ff" xlink:to="loc_suns_CurrentExpectedCreditLossesReserveMember_019d2532-c1f5-7afc-a0eb-3ef3ff0524b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019e163b-ced7-74ad-b542-cdaca40131d6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:to="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019e163b-ced7-74ad-b542-cdaca40131d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019e163b-ced7-74ad-b542-cdaca40131d6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019e163b-ced7-74ad-b542-cdaca40131d6" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019e163b-ced7-74ad-b542-cdaca40131d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019e163b-ced7-7768-83db-433d150940f3" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019e163b-ced7-74ad-b542-cdaca40131d6" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019e163b-ced7-7768-83db-433d150940f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_HospitalityMember_019e163b-ced7-725d-807d-81384acb4387" xlink:href="suns-20260331.xsd#suns_HospitalityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019e163b-ced7-7768-83db-433d150940f3" xlink:to="loc_suns_HospitalityMember_019e163b-ced7-725d-807d-81384acb4387" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019d2532-c1f5-7ddb-b63a-a4ce6196be96" xlink:to="loc_srt_StatementGeographicalAxis_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a" xlink:to="loc_srt_SegmentGeographicalDomain_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e163b-ced7-789a-b57c-a756458c1591" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e163b-ced7-7ea3-ad77-1dcc7b2fcd8a" xlink:to="loc_srt_SegmentGeographicalDomain_019e163b-ced7-789a-b57c-a756458c1591" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_TX_019e163b-ced7-7a97-8f0b-552798321258" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_TX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e163b-ced7-789a-b57c-a756458c1591" xlink:to="loc_stpr_TX_019e163b-ced7-7a97-8f0b-552798321258" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f6-762c-a0bb-7b4c70600ad0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f6-762c-a0bb-7b4c70600ad0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableBasisSpreadOnVariableRate_019d2532-c1f6-7101-96e4-3522b27291b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansReceivableBasisSpreadOnVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_LoansReceivableBasisSpreadOnVariableRate_019d2532-c1f6-7101-96e4-3522b27291b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_FinancingReceivableAllowanceCommitmentBalance_019d2532-c1f6-73ac-b57d-deed6a2cf107" xlink:href="suns-20260331.xsd#suns_FinancingReceivableAllowanceCommitmentBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_suns_FinancingReceivableAllowanceCommitmentBalance_019d2532-c1f6-73ac-b57d-deed6a2cf107" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019d2532-c1f6-7a46-ac52-2e6d01dff34d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019d2532-c1f6-7a46-ac52-2e6d01dff34d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss_019e21d5-4ef7-7acc-982f-1d88b3f6edc1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_FinancingReceivableCoveredAllowanceForCreditLoss_019e21d5-4ef7-7acc-982f-1d88b3f6edc1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019e1640-2feb-7977-9cf8-34b70cdad793" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019e1640-2feb-7977-9cf8-34b70cdad793" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019e163b-ced7-7cd5-ae3a-411b9e2fc659" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019e163b-ced7-7cd5-ae3a-411b9e2fc659" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019e163b-ced7-755a-9a45-dec42042d501" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_NotesReceivableGross_019e163b-ced7-755a-9a45-dec42042d501" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019e1646-32d6-7c71-84b6-777ff63149ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019d2532-c1f5-7b7a-9d63-5093bfb99386" xlink:to="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019e1646-32d6-7c71-84b6-777ff63149ee" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableAllowanceforCreditLossDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableAllowanceforCreditLossDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableAllowanceforCreditLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableImpairedLineItems_019d2532-c1f6-71c9-a2a8-a2749a3ef5cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableImpairedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_019d2532-c1f6-771c-8f3a-47f4caa91683" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfImpairedFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_019d2532-c1f6-71c9-a2a8-a2749a3ef5cc" xlink:to="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_019d2532-c1f6-771c-8f3a-47f4caa91683" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f6-77d1-a5af-97f33364828c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_019d2532-c1f6-771c-8f3a-47f4caa91683" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f6-77d1-a5af-97f33364828c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-77d1-a5af-97f33364828c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f6-77d1-a5af-97f33364828c" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-77d1-a5af-97f33364828c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-7de8-8581-017a7b2b6505" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019d2532-c1f6-77d1-a5af-97f33364828c" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-7de8-8581-017a7b2b6505" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_FundedLoanCommitmentMember_019d2532-c1f6-7320-8de8-f644009f1b19" xlink:href="suns-20260331.xsd#suns_FundedLoanCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-7de8-8581-017a7b2b6505" xlink:to="loc_suns_FundedLoanCommitmentMember_019d2532-c1f6-7320-8de8-f644009f1b19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnfundedLoanCommitmentMember_019d2532-c1f6-7dd5-82d3-4091ac118826" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnfundedLoanCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019d2532-c1f6-7de8-8581-017a7b2b6505" xlink:to="loc_us-gaap_UnfundedLoanCommitmentMember_019d2532-c1f6-7dd5-82d3-4091ac118826" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f6-70ba-95bf-c6b2d7639186" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_019d2532-c1f6-771c-8f3a-47f4caa91683" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f6-70ba-95bf-c6b2d7639186" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f6-70ba-95bf-c6b2d7639186_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f6-70ba-95bf-c6b2d7639186" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f6-70ba-95bf-c6b2d7639186_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f6-7470-8adc-7516ebf273d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019d2532-c1f6-70ba-95bf-c6b2d7639186" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f6-7470-8adc-7516ebf273d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_CurrentExpectedCreditLossesReserveMember_019d2532-c1f6-74e7-b320-072af4cdcdbf" xlink:href="suns-20260331.xsd#suns_CurrentExpectedCreditLossesReserveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019d2532-c1f6-7470-8adc-7516ebf273d1" xlink:to="loc_suns_CurrentExpectedCreditLossesReserveMember_019d2532-c1f6-74e7-b320-072af4cdcdbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_019d2532-c1f6-71c9-a2a8-a2749a3ef5cc" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f6-7bbd-a844-d34fd53b1fd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f6-7bbd-a844-d34fd53b1fd1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019d2532-c1f6-70a0-8e84-01bbbbb1a6fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019d2532-c1f6-70a0-8e84-01bbbbb1a6fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019d2532-c1f6-7ea5-ae81-ee4c8fe22c1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019d2532-c1f6-7ea5-ae81-ee4c8fe22c1e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_019d2532-c1f6-7ae1-8ad7-6f92ae26e477" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019d2532-c1f6-7b57-99fb-e8fc6bcdc2bd" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_019d2532-c1f6-7ae1-8ad7-6f92ae26e477" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019d2532-c1f6-7db3-b457-06a2a5531bf3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableCreditQualityIndicatorsDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableCreditQualityIndicatorsDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/CURRENTEXPECTEDCREDITLOSSESScheduleofFinancingReceivableCreditQualityIndicatorsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019d2532-c1f6-71a2-974d-93d9a46a0fc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019d2532-c1f6-7767-a70d-d491b0ca35c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019d2532-c1f6-71a2-974d-93d9a46a0fc4" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019d2532-c1f6-7767-a70d-d491b0ca35c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_019d2532-c1f6-7334-b331-f7d5eda80296" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019d2532-c1f6-7767-a70d-d491b0ca35c0" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_019d2532-c1f6-7334-b331-f7d5eda80296" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7334-b331-f7d5eda80296_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019d2532-c1f6-7334-b331-f7d5eda80296" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7334-b331-f7d5eda80296_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019d2532-c1f6-7334-b331-f7d5eda80296" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_RiskLevelVeryLowMember_019d2532-c1f6-7b0d-b3d2-637e93d43620" xlink:href="suns-20260331.xsd#suns_RiskLevelVeryLowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:to="loc_suns_RiskLevelVeryLowMember_019d2532-c1f6-7b0d-b3d2-637e93d43620" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RiskLevelLowMember_019d2532-c1f6-78e9-8f22-dc6e29e537f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RiskLevelLowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:to="loc_us-gaap_RiskLevelLowMember_019d2532-c1f6-78e9-8f22-dc6e29e537f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RiskLevelMediumMember_019d2532-c1f6-7323-8852-b627445e3e9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RiskLevelMediumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:to="loc_us-gaap_RiskLevelMediumMember_019d2532-c1f6-7323-8852-b627445e3e9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RiskLevelHighMember_019d2532-c1f6-7a83-8e3f-b6a234b491f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RiskLevelHighMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:to="loc_us-gaap_RiskLevelHighMember_019d2532-c1f6-7a83-8e3f-b6a234b491f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_RiskLevelImpairedLossLikelyMember_019d2532-c1f6-7925-bca6-e0f92c1adfa8" xlink:href="suns-20260331.xsd#suns_RiskLevelImpairedLossLikelyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019d2532-c1f6-7550-b52f-7785d25c3b57" xlink:to="loc_suns_RiskLevelImpairedLossLikelyMember_019d2532-c1f6-7925-bca6-e0f92c1adfa8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019d2532-c1f6-71a2-974d-93d9a46a0fc4" xlink:to="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019d2532-c1f6-7af4-925a-9777f00efbed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019d2532-c1f6-7af4-925a-9777f00efbed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019d2532-c1f6-7112-bb4b-4c52bd200753" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019d2532-c1f6-7112-bb4b-4c52bd200753" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019d627f-5072-7990-9581-c63117d5253d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:to="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019d627f-5072-7990-9581-c63117d5253d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentAndFinancingReceivableBeforeAllowanceForCreditLoss_019d2532-c1f6-7cfd-ba62-eb68cca9a821" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentAndFinancingReceivableBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableBeforeAllowanceForCreditLossByOriginationYearAbstract_019e1644-405d-754b-bf2d-95b753255ddb" xlink:to="loc_suns_LoansHeldForInvestmentAndFinancingReceivableBeforeAllowanceForCreditLoss_019d2532-c1f6-7cfd-ba62-eb68cca9a821" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019d2532-c1f6-71a2-974d-93d9a46a0fc4" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff_019e1641-7125-724b-ba53-5cc461ab2d40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:to="loc_us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff_019e1641-7125-724b-ba53-5cc461ab2d40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019e1641-b59d-7c83-a0e9-78f377e4d57c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:to="loc_us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019e1641-b59d-7c83-a0e9-78f377e4d57c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019e1642-0a60-7096-bab3-43c0904fcd7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:to="loc_us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019e1642-0a60-7096-bab3-43c0904fcd7e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019e1642-f3b2-743b-91e7-08c147fa79ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019e1643-d562-7327-b9f3-7835689c15cb" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019e1642-f3b2-743b-91e7-08c147fa79ab" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURENarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURENarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURENarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96de-430d-7bbd-b8a0-fc41cf53481a" 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_019d96de-430d-7ed2-bd2a-077a210b0b3b" 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_019d96de-430d-7bbd-b8a0-fc41cf53481a" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019d96de-430d-7ed2-bd2a-077a210b0b3b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019d96de-430d-7667-bc61-de4f7b0ffdd6" 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_019d96de-430d-7ed2-bd2a-077a210b0b3b" xlink:to="loc_srt_CounterpartyNameAxis_019d96de-430d-7667-bc61-de4f7b0ffdd6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d96de-430d-7667-bc61-de4f7b0ffdd6_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_019d96de-430d-7667-bc61-de4f7b0ffdd6" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d96de-430d-7667-bc61-de4f7b0ffdd6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d96de-430d-735b-840d-9d74d31b4f12" 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_019d96de-430d-7667-bc61-de4f7b0ffdd6" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d96de-430d-735b-840d-9d74d31b4f12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_TCGREAgentMember_019d96de-430d-7074-a998-ae7b787fb0ef" xlink:href="suns-20260331.xsd#suns_TCGREAgentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019d96de-430d-735b-840d-9d74d31b4f12" xlink:to="loc_suns_TCGREAgentMember_019d96de-430d-7074-a998-ae7b787fb0ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d96de-430d-77e3-88b9-1ca1b688f662" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019d96de-430d-7ed2-bd2a-077a210b0b3b" xlink:to="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d96de-430d-77e3-88b9-1ca1b688f662" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d96de-430d-77e3-88b9-1ca1b688f662_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d96de-430d-77e3-88b9-1ca1b688f662" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d96de-430d-77e3-88b9-1ca1b688f662_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d96de-430d-7be9-b001-f4d7a1195a27" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019d96de-430d-77e3-88b9-1ca1b688f662" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d96de-430d-7be9-b001-f4d7a1195a27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_HospitalityMember_019d96de-430d-70a8-a5bf-1249fea855ce" xlink:href="suns-20260331.xsd#suns_HospitalityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019d96de-430d-7be9-b001-f4d7a1195a27" xlink:to="loc_suns_HospitalityMember_019d96de-430d-70a8-a5bf-1249fea855ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019d96de-430d-7db9-9ff9-29fc46c2938b" 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_019d96de-430d-7ed2-bd2a-077a210b0b3b" xlink:to="loc_srt_OwnershipAxis_019d96de-430d-7db9-9ff9-29fc46c2938b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019d96de-430d-7db9-9ff9-29fc46c2938b_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_019d96de-430d-7db9-9ff9-29fc46c2938b" xlink:to="loc_srt_OwnershipDomain_019d96de-430d-7db9-9ff9-29fc46c2938b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019d96de-430d-7403-bc8b-1b3b8290713c" 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_019d96de-430d-7db9-9ff9-29fc46c2938b" xlink:to="loc_srt_OwnershipDomain_019d96de-430d-7403-bc8b-1b3b8290713c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SanAntonioPropertyMember_019d96de-430d-7e87-bf6a-821a6d183183" xlink:href="suns-20260331.xsd#suns_SanAntonioPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019d96de-430d-7403-bc8b-1b3b8290713c" xlink:to="loc_suns_SanAntonioPropertyMember_019d96de-430d-7e87-bf6a-821a6d183183" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019e06d6-a57e-7c0b-a4d8-6f8e301c5521" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestNetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96de-430d-7bbd-b8a0-fc41cf53481a" xlink:to="loc_us-gaap_ReceivableWithImputedInterestNetAmount_019e06d6-a57e-7c0b-a4d8-6f8e301c5521" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentsJointVentures_019d96de-430d-76df-9289-9e9c24808f1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInvestmentsJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96de-430d-7bbd-b8a0-fc41cf53481a" xlink:to="loc_us-gaap_RealEstateInvestmentsJointVentures_019d96de-430d-76df-9289-9e9c24808f1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest_019d96de-430d-761e-b8b1-86956b64c3a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96de-430d-7bbd-b8a0-fc41cf53481a" xlink:to="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest_019d96de-430d-761e-b8b1-86956b64c3a7" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURESummaryofInvestmentinUnconsolidatedRealEstateJointVentureDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURESummaryofInvestmentinUnconsolidatedRealEstateJointVentureDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/INVESTMENTINUNCONSOLIDATEDREALESTATEJOINTVENTURESummaryofInvestmentinUnconsolidatedRealEstateJointVentureDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96ee-3ec1-77d0-b4d0-30cd76efeeec" 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_019d96ee-3ec1-7b06-bc0e-771b1425927f" 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_019d96ee-3ec1-77d0-b4d0-30cd76efeeec" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019d96ee-3ec1-7b06-bc0e-771b1425927f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d96f0-1b31-7537-9d21-b36e5bd5026c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019d96ee-3ec1-7b06-bc0e-771b1425927f" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d96f0-1b31-7537-9d21-b36e5bd5026c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019d96f0-1b31-7537-9d21-b36e5bd5026c_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d96f0-1b31-7537-9d21-b36e5bd5026c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019d96f0-1b31-7537-9d21-b36e5bd5026c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019d96f0-1b31-789e-a76b-55d7df73fcc7" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019d96f0-1b31-7537-9d21-b36e5bd5026c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019d96f0-1b31-789e-a76b-55d7df73fcc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_A123LexAveHotelHoldingsLLCMember_019d96f0-29fd-7244-9a82-50f5de2b4699" xlink:href="suns-20260331.xsd#suns_A123LexAveHotelHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019d96f0-1b31-789e-a76b-55d7df73fcc7" xlink:to="loc_suns_A123LexAveHotelHoldingsLLCMember_019d96f0-29fd-7244-9a82-50f5de2b4699" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019d96ee-3ec1-7bc7-8b46-af4e5dc6ee27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96ee-3ec1-77d0-b4d0-30cd76efeeec" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019d96ee-3ec1-7bc7-8b46-af4e5dc6ee27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019d96e2-25e3-74ca-8f1a-f2de198999e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019d96ee-3ec1-77d0-b4d0-30cd76efeeec" xlink:to="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019d96e2-25e3-74ca-8f1a-f2de198999e2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/DEBTNarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#DEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/DEBTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019d9a25-a903-7957-8965-ebce0e21d246" 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_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:to="loc_us-gaap_CreditFacilityAxis_019d9a25-a903-7957-8965-ebce0e21d246" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d9a25-a903-7957-8965-ebce0e21d246_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_019d9a25-a903-7957-8965-ebce0e21d246" xlink:to="loc_us-gaap_CreditFacilityDomain_019d9a25-a903-7957-8965-ebce0e21d246_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d9a25-a903-7b26-ad4b-4257d73576b7" 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_019d9a25-a903-7957-8965-ebce0e21d246" xlink:to="loc_us-gaap_CreditFacilityDomain_019d9a25-a903-7b26-ad4b-4257d73576b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019d9a25-a903-7dd6-93aa-18cd9d4eacdc" 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_019d9a25-a903-7b26-ad4b-4257d73576b7" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019d9a25-a903-7dd6-93aa-18cd9d4eacdc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d9a25-a903-7d40-9132-47fe85792a25" 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_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d9a25-a903-7d40-9132-47fe85792a25" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-7d40-9132-47fe85792a25_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_019d9a25-a903-7d40-9132-47fe85792a25" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-7d40-9132-47fe85792a25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-774f-b2e8-5f375537a5b2" 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_019d9a25-a903-7d40-9132-47fe85792a25" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-774f-b2e8-5f375537a5b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_RevolvingCreditFacilityOtherMember_019d9a25-a903-704e-9d76-7a06185fb960" xlink:href="suns-20260331.xsd#suns_RevolvingCreditFacilityOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-774f-b2e8-5f375537a5b2" xlink:to="loc_suns_RevolvingCreditFacilityOtherMember_019d9a25-a903-704e-9d76-7a06185fb960" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SRTFRevolvingCreditFacilityMember_019d9a26-4d21-76cd-89b2-9460d435690a" xlink:href="suns-20260331.xsd#suns_SRTFRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d9a25-a903-774f-b2e8-5f375537a5b2" xlink:to="loc_suns_SRTFRevolvingCreditFacilityMember_019d9a26-4d21-76cd-89b2-9460d435690a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d9a25-a903-77c5-831e-b69708d7e0ba" 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_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d9a25-a903-77c5-831e-b69708d7e0ba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d9a25-a903-77c5-831e-b69708d7e0ba_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_019d9a25-a903-77c5-831e-b69708d7e0ba" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d9a25-a903-77c5-831e-b69708d7e0ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d9a25-a903-7b26-9332-755c578c02af" 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_019d9a25-a903-77c5-831e-b69708d7e0ba" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d9a25-a903-7b26-9332-755c578c02af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d9a25-a903-7013-9fe7-b5dcc148ef5e" 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_019d9a25-a903-7b26-9332-755c578c02af" xlink:to="loc_us-gaap_SecuredDebtMember_019d9a25-a903-7013-9fe7-b5dcc148ef5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019d9a26-4d21-7741-a981-a5724232a123" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d9a25-a903-7b26-9332-755c578c02af" xlink:to="loc_us-gaap_UnsecuredDebtMember_019d9a26-4d21-7741-a981-a5724232a123" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019d9a25-dd6d-7bc8-8032-ffcec33d1631" 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_LineOfCreditFacilityTable_019d9a25-a903-711a-89dd-2ef910089cc2" xlink:to="loc_us-gaap_VariableRateAxis_019d9a25-dd6d-7bc8-8032-ffcec33d1631" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d9a25-dd6d-7bc8-8032-ffcec33d1631_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_019d9a25-dd6d-7bc8-8032-ffcec33d1631" xlink:to="loc_us-gaap_VariableRateDomain_019d9a25-dd6d-7bc8-8032-ffcec33d1631_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019d9a25-dd6d-7763-892a-b7ef66a01ca1" 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_019d9a25-dd6d-7bc8-8032-ffcec33d1631" xlink:to="loc_us-gaap_VariableRateDomain_019d9a25-dd6d-7763-892a-b7ef66a01ca1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d9a25-dd6d-77a1-a57b-924f5994b191" 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_019d9a25-dd6d-7763-892a-b7ef66a01ca1" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019d9a25-dd6d-77a1-a57b-924f5994b191" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019d9a25-dd6d-7df8-a711-0392d72337f9" 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_019d9a25-dd6d-7763-892a-b7ef66a01ca1" xlink:to="loc_us-gaap_BaseRateMember_019d9a25-dd6d-7df8-a711-0392d72337f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d9a25-a903-77ff-857d-b76bc1c86e3c" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019d9a25-a903-77ff-857d-b76bc1c86e3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_019d9a25-c3b1-7eee-ae6c-3cb79cad16ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_019d9a25-c3b1-7eee-ae6c-3cb79cad16ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LineOfCreditFacilityAccordionFeatureIncreaseLimit_019d9a25-c3b1-723c-9714-eaa5bcbf5c69" xlink:href="suns-20260331.xsd#suns_LineOfCreditFacilityAccordionFeatureIncreaseLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_LineOfCreditFacilityAccordionFeatureIncreaseLimit_019d9a25-c3b1-723c-9714-eaa5bcbf5c69" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d9a25-dd6d-7ef4-b65b-0e374c12bad9" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019d9a25-dd6d-7ef4-b65b-0e374c12bad9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d9a25-dd6d-7d41-b033-591166025657" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019d9a25-dd6d-7d41-b033-591166025657" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_DebtInstrumentAgentFee_019d9a25-faf6-7d20-abc1-645376ad6460" xlink:href="suns-20260331.xsd#suns_DebtInstrumentAgentFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_DebtInstrumentAgentFee_019d9a25-faf6-7d20-abc1-645376ad6460" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_019d9a25-faf6-7c8d-9ecc-46c2a5f72ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_019d9a25-faf6-7c8d-9ecc-46c2a5f72ad9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_019d9a25-faf6-7643-8c5f-32f6bb1ed203" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_019d9a25-faf6-7643-8c5f-32f6bb1ed203" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LineOfCreditFacilityLiquidityCovenantMinimumAmount_019d9a26-1bec-7eff-98c4-8363f725ee35" xlink:href="suns-20260331.xsd#suns_LineOfCreditFacilityLiquidityCovenantMinimumAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_LineOfCreditFacilityLiquidityCovenantMinimumAmount_019d9a26-1bec-7eff-98c4-8363f725ee35" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LineOfCreditFacilityLiquidityCovenantOutstandingObligationsPercent_019d9a26-1bec-7f8e-8ce5-a4189ebe79e4" xlink:href="suns-20260331.xsd#suns_LineOfCreditFacilityLiquidityCovenantOutstandingObligationsPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_LineOfCreditFacilityLiquidityCovenantOutstandingObligationsPercent_019d9a26-1bec-7f8e-8ce5-a4189ebe79e4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LineOfCreditFacilityCovenantQuarterlyDebtServiceCoverageRatioMinimum_019d9a26-1bec-7012-b717-6aad3fd7f3a2" xlink:href="suns-20260331.xsd#suns_LineOfCreditFacilityCovenantQuarterlyDebtServiceCoverageRatioMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_LineOfCreditFacilityCovenantQuarterlyDebtServiceCoverageRatioMinimum_019d9a26-1bec-7012-b717-6aad3fd7f3a2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LineOfCreditFacilityCovenantLeverageRatioMaximum_019d9a26-1bec-7414-8fcf-6029b2340566" xlink:href="suns-20260331.xsd#suns_LineOfCreditFacilityCovenantLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_suns_LineOfCreditFacilityCovenantLeverageRatioMaximum_019d9a26-1bec-7414-8fcf-6029b2340566" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019d9a26-3366-768a-9533-000339155a47" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCredit_019d9a26-3366-768a-9533-000339155a47" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019d9a26-3366-7a68-b54b-795a601b253c" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019d9a26-3366-7a68-b54b-795a601b253c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_019d9a26-3366-76c4-bb6a-d564e772b723" 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_LineOfCreditFacilityLineItems_019d9a25-a903-7eee-87e5-e4235b7ead4e" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_019d9a26-3366-76c4-bb6a-d564e772b723" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/DEBTScheduleofInterestExpenseDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#DEBTScheduleofInterestExpenseDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/DEBTScheduleofInterestExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019d2532-c1f6-7d4f-9631-b7d145619c75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019d2532-c1f6-7d4f-9631-b7d145619c75" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019d2532-c1f6-722f-8675-764af9c4eb1e" 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_LineOfCreditFacilityTable_019d2532-c1f6-7d4f-9631-b7d145619c75" xlink:to="loc_us-gaap_CreditFacilityAxis_019d2532-c1f6-722f-8675-764af9c4eb1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d2532-c1f6-722f-8675-764af9c4eb1e_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_019d2532-c1f6-722f-8675-764af9c4eb1e" xlink:to="loc_us-gaap_CreditFacilityDomain_019d2532-c1f6-722f-8675-764af9c4eb1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019d2532-c1f6-758a-a6d5-17095c13063c" 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_019d2532-c1f6-722f-8675-764af9c4eb1e" xlink:to="loc_us-gaap_CreditFacilityDomain_019d2532-c1f6-758a-a6d5-17095c13063c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019d2532-c1f6-7b37-9c76-a5f8bb33b7f2" 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_019d2532-c1f6-758a-a6d5-17095c13063c" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019d2532-c1f6-7b37-9c76-a5f8bb33b7f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019d2532-c1f6-739a-9473-3a250916c6cc" 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_LineOfCreditFacilityTable_019d2532-c1f6-7d4f-9631-b7d145619c75" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019d2532-c1f6-739a-9473-3a250916c6cc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2532-c1f6-739a-9473-3a250916c6cc_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_019d2532-c1f6-739a-9473-3a250916c6cc" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2532-c1f6-739a-9473-3a250916c6cc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019d2532-c1f6-7c0c-b9e5-dc0ffb06efec" 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_019d2532-c1f6-739a-9473-3a250916c6cc" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019d2532-c1f6-7c0c-b9e5-dc0ffb06efec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019d2532-c1f6-75b1-8899-900141e2d586" 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_019d2532-c1f6-7c0c-b9e5-dc0ffb06efec" xlink:to="loc_us-gaap_SecuredDebtMember_019d2532-c1f6-75b1-8899-900141e2d586" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019d2532-c1f6-7778-a901-61188ab4afec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019d2532-c1f6-7c0c-b9e5-dc0ffb06efec" xlink:to="loc_us-gaap_UnsecuredDebtMember_019d2532-c1f6-7778-a901-61188ab4afec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4" 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_LineOfCreditFacilityTable_019d2532-c1f6-7d4f-9631-b7d145619c75" xlink:to="loc_us-gaap_DebtInstrumentAxis_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4_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_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7db8-91d1-ecc7310e49c3" 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_019d2532-c1f6-7a6d-aa0e-c8354b3df5a4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7db8-91d1-ecc7310e49c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_RevolvingCreditFacilityOtherMember_019d2532-c1f6-7f31-b303-eca68deb9f42" xlink:href="suns-20260331.xsd#suns_RevolvingCreditFacilityOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7db8-91d1-ecc7310e49c3" xlink:to="loc_suns_RevolvingCreditFacilityOtherMember_019d2532-c1f6-7f31-b303-eca68deb9f42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SRTFRevolvingCreditFacilityMember_019d2532-c1f6-71d0-b398-e855ca5d075f" xlink:href="suns-20260331.xsd#suns_SRTFRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019d2532-c1f6-7db8-91d1-ecc7310e49c3" xlink:to="loc_suns_SRTFRevolvingCreditFacilityMember_019d2532-c1f6-71d0-b398-e855ca5d075f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019d2532-c1f6-71e6-b822-ee0b46ebfb21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:to="loc_us-gaap_InterestExpenseDebt_019d2532-c1f6-71e6-b822-ee0b46ebfb21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeeAmount_019d2532-c1f6-74b8-9563-3cc8dca54176" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeeAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeeAmount_019d2532-c1f6-74b8-9563-3cc8dca54176" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019d2532-c1f6-71d3-a010-e963335858cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019d2532-c1f6-71d3-a010-e963335858cd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_019d2532-c1f6-7abb-8161-c922d565a5b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019d2532-c1f6-7047-bae2-6211f1596875" xlink:to="loc_us-gaap_InterestExpense_019d2532-c1f6-7abb-8161-c922d565a5b9" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYNarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#SHAREHOLDERSEQUITYNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" 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_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" 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_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_019dc33c-00ef-7d2e-a400-75384cf33db1" 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_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_019dc33c-00ef-7d2e-a400-75384cf33db1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-7d2e-a400-75384cf33db1_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_019dc33c-00ef-7d2e-a400-75384cf33db1" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-7d2e-a400-75384cf33db1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-75e4-b7d6-22325241f5fa" 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_019dc33c-00ef-7d2e-a400-75384cf33db1" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-75e4-b7d6-22325241f5fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShelfRegistrationStatementMember_019dc33c-00ef-7681-83ca-4f8b1c6f69e3" xlink:href="suns-20260331.xsd#suns_ShelfRegistrationStatementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-75e4-b7d6-22325241f5fa" xlink:to="loc_suns_ShelfRegistrationStatementMember_019dc33c-00ef-7681-83ca-4f8b1c6f69e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_January2025PublicOfferingMember_019dc33c-2aea-74cf-b882-4a3af8030a10" xlink:href="suns-20260331.xsd#suns_January2025PublicOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-75e4-b7d6-22325241f5fa" xlink:to="loc_suns_January2025PublicOfferingMember_019dc33c-2aea-74cf-b882-4a3af8030a10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_AtTheMarketOfferingProgramMember_019dc33c-4abd-7d9e-b62f-9a14272e8c6f" xlink:href="suns-20260331.xsd#suns_AtTheMarketOfferingProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019dc33c-00ef-75e4-b7d6-22325241f5fa" xlink:to="loc_suns_AtTheMarketOfferingProgramMember_019dc33c-4abd-7d9e-b62f-9a14272e8c6f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019dc33c-6f5e-7b51-a74b-68f1556a7145" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:to="loc_us-gaap_PlanNameAxis_019dc33c-6f5e-7b51-a74b-68f1556a7145" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7b51-a74b-68f1556a7145_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019dc33c-6f5e-7b51-a74b-68f1556a7145" xlink:to="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7b51-a74b-68f1556a7145_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7a4f-9506-e51db09639d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019dc33c-6f5e-7b51-a74b-68f1556a7145" xlink:to="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7a4f-9506-e51db09639d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_DividendReinvestmentPlanMember_019dc33c-6f5e-75d7-bca1-19801cdbc601" xlink:href="suns-20260331.xsd#suns_DividendReinvestmentPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7a4f-9506-e51db09639d2" xlink:to="loc_suns_DividendReinvestmentPlanMember_019dc33c-6f5e-75d7-bca1-19801cdbc601" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_EquityIncentivePlan2024Member_019dc33c-948c-7577-8dc6-698181fc1d78" xlink:href="suns-20260331.xsd#suns_EquityIncentivePlan2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019dc33c-6f5e-7a4f-9506-e51db09639d2" xlink:to="loc_suns_EquityIncentivePlan2024Member_019dc33c-948c-7577-8dc6-698181fc1d78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019dc33c-948c-79d0-a2c4-b541d735eaa4" 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_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:to="loc_us-gaap_AwardTypeAxis_019dc33c-948c-79d0-a2c4-b541d735eaa4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dc33c-948c-79d0-a2c4-b541d735eaa4_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_019dc33c-948c-79d0-a2c4-b541d735eaa4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dc33c-948c-79d0-a2c4-b541d735eaa4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dc33c-948c-7db8-8c08-10566ad21d0d" 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_019dc33c-948c-79d0-a2c4-b541d735eaa4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dc33c-948c-7db8-8c08-10566ad21d0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019dc33c-948c-71b3-8e67-c74f26f047a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dc33c-948c-7db8-8c08-10566ad21d0d" xlink:to="loc_us-gaap_RestrictedStockMember_019dc33c-948c-71b3-8e67-c74f26f047a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_019dc33c-948c-7007-8cb5-c3c352bd3a76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:to="loc_us-gaap_VestingAxis_019dc33c-948c-7007-8cb5-c3c352bd3a76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019dc33c-948c-7007-8cb5-c3c352bd3a76_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_019dc33c-948c-7007-8cb5-c3c352bd3a76" xlink:to="loc_us-gaap_VestingDomain_019dc33c-948c-7007-8cb5-c3c352bd3a76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019dc33c-948c-7acc-89c6-890948936788" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_019dc33c-948c-7007-8cb5-c3c352bd3a76" xlink:to="loc_us-gaap_VestingDomain_019dc33c-948c-7acc-89c6-890948936788" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019dc33c-948c-7269-a0c8-9423ca0df913" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019dc33c-948c-7acc-89c6-890948936788" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019dc33c-948c-7269-a0c8-9423ca0df913" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_019dc33c-948c-7a16-99f7-580dd9f111e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019dc33c-948c-7acc-89c6-890948936788" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_019dc33c-948c-7a16-99f7-580dd9f111e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_019dc33c-948c-78be-980f-fb7d4e745bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019dc33c-948c-7acc-89c6-890948936788" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_019dc33c-948c-78be-980f-fb7d4e745bf5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019dfdb5-0adb-7529-925f-3326902e5011" 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_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dc33b-a1e6-7d3d-bc3a-cad4a0c636b1" xlink:to="loc_srt_RangeAxis_019dfdb5-0adb-7529-925f-3326902e5011" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dfdb5-0adb-7529-925f-3326902e5011_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_019dfdb5-0adb-7529-925f-3326902e5011" xlink:to="loc_srt_RangeMember_019dfdb5-0adb-7529-925f-3326902e5011_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dfdb5-0adb-7f0c-96d4-2677ca29369e" 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_019dfdb5-0adb-7529-925f-3326902e5011" xlink:to="loc_srt_RangeMember_019dfdb5-0adb-7f0c-96d4-2677ca29369e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019dfdb5-2e45-7c66-b133-6e9082d53fa1" 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_019dfdb5-0adb-7f0c-96d4-2677ca29369e" xlink:to="loc_srt_MinimumMember_019dfdb5-2e45-7c66-b133-6e9082d53fa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019dfdb5-4b6f-7a54-a820-7d099219f4c9" 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_019dfdb5-0adb-7f0c-96d4-2677ca29369e" xlink:to="loc_srt_MaximumMember_019dfdb5-4b6f-7a54-a820-7d099219f4c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019dc33b-a1e6-7e0f-a0f5-9506b5cb0543" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019dc33b-a1e6-7e0f-a0f5-9506b5cb0543" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019dc33b-a1e6-7353-b824-61649444e55b" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019dc33b-a1e6-7353-b824-61649444e55b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019dc33b-a1e6-71dc-8bcc-3fbc6add4b77" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019dc33b-a1e6-71dc-8bcc-3fbc6add4b77" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_019dc33b-c16b-75ff-9157-0f766eb16b59" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_019dc33b-c16b-75ff-9157-0f766eb16b59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019dc33b-d769-721c-8a5c-74d97e891d93" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019dc33b-d769-721c-8a5c-74d97e891d93" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019dc33b-d769-7df5-bc8c-3a81a7c72b1e" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_CommonStockSharesIssued_019dc33b-d769-7df5-bc8c-3a81a7c72b1e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019dc33b-d769-73df-aab6-35eccaca37c3" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019dc33b-d769-73df-aab6-35eccaca37c3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SaleOfStockMaximumAggregateOfferingAmount_019dc33c-00ef-7bbb-b374-7b5b28442f8e" xlink:href="suns-20260331.xsd#suns_SaleOfStockMaximumAggregateOfferingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_suns_SaleOfStockMaximumAggregateOfferingAmount_019dc33c-00ef-7bbb-b374-7b5b28442f8e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_019dc33c-2aea-7452-8663-43d55013c9c5" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_019dc33c-2aea-7452-8663-43d55013c9c5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019dc33c-2aea-7b20-a6ef-ee554f17ddcc" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019dc33c-2aea-7b20-a6ef-ee554f17ddcc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019dc33c-2aea-7460-9769-df553f06c464" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019dc33c-2aea-7460-9769-df553f06c464" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SaleOfStockCommissionPercentage_019dc33c-4abd-71fd-9867-4ed5aaed93b8" xlink:href="suns-20260331.xsd#suns_SaleOfStockCommissionPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_suns_SaleOfStockCommissionPercentage_019dc33c-4abd-71fd-9867-4ed5aaed93b8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019dc33c-6f5e-76d4-ac07-78ed7bff206a" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019dc33c-6f5e-76d4-ac07-78ed7bff206a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_019dc33c-6f5e-71c2-bca3-58cc56e470e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_019dc33c-6f5e-71c2-bca3-58cc56e470e1" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019dc33c-948c-76a6-ad0c-20ecd4f45430" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019dc33c-948c-76a6-ad0c-20ecd4f45430" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019dc33c-948c-711a-a19b-34608c4272bc" 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_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019dc33c-948c-711a-a19b-34608c4272bc" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019dc33c-948c-739f-ad4d-13da863f3917" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019dc33c-948c-739f-ad4d-13da863f3917" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019dc33c-d7a9-7d20-9d57-86766816070e" 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_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019dc33c-d7a9-7d20-9d57-86766816070e" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareLimit_019dc33c-efb2-7491-96c3-3e63028395d2" xlink:href="suns-20260331.xsd#suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareLimit_019dc33c-efb2-7491-96c3-3e63028395d2" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_019dc33d-1046-73bc-a68c-4a6aedef7cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_019dc33d-1046-73bc-a68c-4a6aedef7cbd" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019dc33d-1046-7185-9272-9f9cc77f111e" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019dc33d-1046-7185-9272-9f9cc77f111e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019dc33d-1046-71f3-b8ea-ed2b6c08dfd7" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019dc33d-1046-71f3-b8ea-ed2b6c08dfd7" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019dc33d-1046-7163-9082-a820cb90d74e" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019dc33d-1046-7163-9082-a820cb90d74e" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019dc33d-2e1a-7afa-a7fd-372bdbeab3d0" 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_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019dc33d-2e1a-7afa-a7fd-372bdbeab3d0" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019dc33d-2e1a-75e7-b342-5415b311aa5b" 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_019dc33b-a1e6-7ffb-a18d-452371c0c108" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019dc33d-2e1a-75e7-b342-5415b311aa5b" xlink:type="arc" order="24"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYScheduleofNonvestedShareActivityDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#SHAREHOLDERSEQUITYScheduleofNonvestedShareActivityDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYScheduleofNonvestedShareActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" 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_019d2532-c1f6-7d49-b646-23c7156ae8f0" 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_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2532-c1f6-7d49-b646-23c7156ae8f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0" 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_019d2532-c1f6-7d49-b646-23c7156ae8f0" xlink:to="loc_us-gaap_AwardTypeAxis_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0_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_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-733d-915e-af263027742f" 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_019d2532-c1f6-7c9e-9beb-4a6bbf2b27e0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-733d-915e-af263027742f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019d2532-c1f6-71ec-93ea-1097d21cff9f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-733d-915e-af263027742f" xlink:to="loc_us-gaap_RestrictedStockMember_019d2532-c1f6-71ec-93ea-1097d21cff9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedCumulative_019d2532-c1f6-7421-b401-92a3dce736af" xlink:href="suns-20260331.xsd#suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedCumulative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedCumulative_019d2532-c1f6-7421-b401-92a3dce736af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedCumulative_019d2532-c1f6-7629-8ed9-4d5f6dfd9e38" xlink:href="suns-20260331.xsd#suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedCumulative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedCumulative_019d2532-c1f6-7629-8ed9-4d5f6dfd9e38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedCumulative_019d2532-c1f6-7999-92d4-1b9854196e7b" xlink:href="suns-20260331.xsd#suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedCumulative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedCumulative_019d2532-c1f6-7999-92d4-1b9854196e7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedCumulative_019d2532-c1f6-7bc2-99e6-71586b56f31d" xlink:href="suns-20260331.xsd#suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedCumulative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_suns_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedCumulative_019d2532-c1f6-7bc2-99e6-71586b56f31d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019d2532-c1f6-7a7e-b6bc-3f251f64da96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-7955-9f30-2bb9fedbc24d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019d2532-c1f6-7a7e-b6bc-3f251f64da96" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYScheduleofRestrictedStockAwardsActivityDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#SHAREHOLDERSEQUITYScheduleofRestrictedStockAwardsActivityDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/SHAREHOLDERSEQUITYScheduleofRestrictedStockAwardsActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-78f5-8cc3-9211ded5a5a1" 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_019d2532-c1f6-7acf-980d-ab497a2f8c5a" 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_019d2532-c1f6-78f5-8cc3-9211ded5a5a1" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019d2532-c1f6-7acf-980d-ab497a2f8c5a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019d2532-c1f6-7f56-b05c-ba4e9f54dceb" 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_019d2532-c1f6-7acf-980d-ab497a2f8c5a" xlink:to="loc_us-gaap_AwardTypeAxis_019d2532-c1f6-7f56-b05c-ba4e9f54dceb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7f56-b05c-ba4e9f54dceb_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_019d2532-c1f6-7f56-b05c-ba4e9f54dceb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7f56-b05c-ba4e9f54dceb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7a27-bdaf-c0ed7abaac09" 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_019d2532-c1f6-7f56-b05c-ba4e9f54dceb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7a27-bdaf-c0ed7abaac09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019d2532-c1f6-7bdf-8e82-af5030e95faa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019d2532-c1f6-7a27-bdaf-c0ed7abaac09" xlink:to="loc_us-gaap_RestrictedStockMember_019d2532-c1f6-7bdf-8e82-af5030e95faa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019d2532-c1f6-78f5-8cc3-9211ded5a5a1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019d2532-c1f6-71c8-a000-b64e893da5c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019d2532-c1f6-71c8-a000-b64e893da5c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019d2532-c1f6-795e-bfc6-2ae5d33c6984" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019d2532-c1f6-795e-bfc6-2ae5d33c6984" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d2532-c1f6-7439-ae1f-b861b4056cd4" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019d2532-c1f6-7439-ae1f-b861b4056cd4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019d2532-c1f6-7715-8e5a-6170282ab987" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019d2532-c1f6-7386-84c7-7e53d67ea479" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019d2532-c1f6-7715-8e5a-6170282ab987" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019d2532-c1f6-75e3-bcbe-3c243a9a5f13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2532-c1f6-7415-94a8-04b84f48c316" 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_019d2532-c1f6-78f5-8cc3-9211ded5a5a1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019d2532-c1f6-7415-94a8-04b84f48c316" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2532-c1f6-7049-9ed7-40d5fdb5caae" 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_019d2532-c1f6-7415-94a8-04b84f48c316" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2532-c1f6-7049-9ed7-40d5fdb5caae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019d2532-c1f6-72aa-9b91-bf867f10e3da" 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_019d2532-c1f6-7415-94a8-04b84f48c316" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019d2532-c1f6-72aa-9b91-bf867f10e3da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2532-c1f6-7dbd-aa24-2984ba05c572" 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_019d2532-c1f6-7415-94a8-04b84f48c316" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019d2532-c1f6-7dbd-aa24-2984ba05c572" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019d2532-c1f6-704b-b180-00ce06df1953" 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_019d2532-c1f6-7415-94a8-04b84f48c316" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019d2532-c1f6-704b-b180-00ce06df1953" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019d2532-c1f6-7ca0-a368-705dc126fbd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/FAIRVALUEScheduleofBookValueandFairValueoftheFinancialInstrumentsDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#FAIRVALUEScheduleofBookValueandFairValueoftheFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/FAIRVALUEScheduleofBookValueandFairValueoftheFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019d2532-c1f6-7163-ab2f-2cd1e13286f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019d2532-c1f6-7b4a-aa3c-2b689f85664b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019d2532-c1f6-7163-ab2f-2cd1e13286f4" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019d2532-c1f6-7b4a-aa3c-2b689f85664b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019d2532-c1f6-724f-9825-aed414dd9892" 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_FairValueByBalanceSheetGroupingTable_019d2532-c1f6-7b4a-aa3c-2b689f85664b" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019d2532-c1f6-724f-9825-aed414dd9892" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019d2532-c1f6-724f-9825-aed414dd9892_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_019d2532-c1f6-724f-9825-aed414dd9892" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019d2532-c1f6-724f-9825-aed414dd9892_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019d2532-c1f6-72bf-aa30-16fdda49d456" 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_019d2532-c1f6-724f-9825-aed414dd9892" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019d2532-c1f6-72bf-aa30-16fdda49d456" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019d2532-c1f6-7784-a04e-561cbbfbc38e" 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_019d2532-c1f6-72bf-aa30-16fdda49d456" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019d2532-c1f6-7784-a04e-561cbbfbc38e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019d2532-c1f6-7b7d-902f-27b28dde2f04" 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_019d2532-c1f6-7784-a04e-561cbbfbc38e" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019d2532-c1f6-7b7d-902f-27b28dde2f04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019d2532-c1f6-7527-ae5e-e912e412ddc6" 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_019d2532-c1f6-7784-a04e-561cbbfbc38e" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019d2532-c1f6-7527-ae5e-e912e412ddc6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2532-c1f6-7c45-b669-d443c085ca79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019d2532-c1f6-7163-ab2f-2cd1e13286f4" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2532-c1f6-7c45-b669-d443c085ca79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019d2532-c1f6-7e51-8117-8dffe32b259c" 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_AssetsFairValueDisclosureAbstract_019d2532-c1f6-7c45-b669-d443c085ca79" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019d2532-c1f6-7e51-8117-8dffe32b259c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_LoansHeldForInvestmentFairValue_019d2532-c1f6-7845-bcdf-400c8b14d878" xlink:href="suns-20260331.xsd#suns_LoansHeldForInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2532-c1f6-7c45-b669-d443c085ca79" xlink:to="loc_suns_LoansHeldForInvestmentFairValue_019d2532-c1f6-7845-bcdf-400c8b14d878" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019e0628-6411-71e5-a4f1-af4fc8cde892" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019d2532-c1f6-7c45-b669-d443c085ca79" xlink:to="loc_us-gaap_RealEstateInvestmentsUnconsolidatedRealEstateAndOtherJointVentures_019e0628-6411-71e5-a4f1-af4fc8cde892" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#RELATEDPARTYTRANSACTIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c1f6-70e8-84d1-7024518462a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c1f6-70e8-84d1-7024518462a8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c1f6-7cef-97db-8570b521a589" 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_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c1f6-70e8-84d1-7024518462a8" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c1f6-7cef-97db-8570b521a589" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-7cef-97db-8570b521a589_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_019d2532-c1f6-7cef-97db-8570b521a589" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-7cef-97db-8570b521a589_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-752a-a5f1-dd1fd10dbc4f" 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_019d2532-c1f6-7cef-97db-8570b521a589" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-752a-a5f1-dd1fd10dbc4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2532-c1f6-7240-9538-f7c9645da7d2" 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_019d2532-c1f6-752a-a5f1-dd1fd10dbc4f" xlink:to="loc_us-gaap_RelatedPartyMember_019d2532-c1f6-7240-9538-f7c9645da7d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ManagementMember_019d2532-c1f6-77cf-9b35-1346d986aa51" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ManagementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-752a-a5f1-dd1fd10dbc4f" xlink:to="loc_srt_ManagementMember_019d2532-c1f6-77cf-9b35-1346d986aa51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_019d2532-c1f6-753f-8cf3-bce19229bee4" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019d2532-c1f6-752a-a5f1-dd1fd10dbc4f" xlink:to="loc_srt_AffiliatedEntityMember_019d2532-c1f6-753f-8cf3-bce19229bee4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019d2532-c1f6-7228-93c2-f1f720a4dfce" 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_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c1f6-70e8-84d1-7024518462a8" xlink:to="loc_srt_OwnershipAxis_019d2532-c1f6-7228-93c2-f1f720a4dfce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019d2532-c1f6-7228-93c2-f1f720a4dfce_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_019d2532-c1f6-7228-93c2-f1f720a4dfce" xlink:to="loc_srt_OwnershipDomain_019d2532-c1f6-7228-93c2-f1f720a4dfce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019d2532-c1f6-7630-b216-458540a32660" 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_019d2532-c1f6-7228-93c2-f1f720a4dfce" xlink:to="loc_srt_OwnershipDomain_019d2532-c1f6-7630-b216-458540a32660" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_SanAntonioPropertyMember_019d2532-c1f6-7464-ab2b-34800134d45a" xlink:href="suns-20260331.xsd#suns_SanAntonioPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019d2532-c1f6-7630-b216-458540a32660" xlink:to="loc_suns_SanAntonioPropertyMember_019d2532-c1f6-7464-ab2b-34800134d45a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_PercentageOfBaseManagementFees_019d2532-c1f6-753f-91e9-56fa18594f20" xlink:href="suns-20260331.xsd#suns_PercentageOfBaseManagementFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_suns_PercentageOfBaseManagementFees_019d2532-c1f6-753f-91e9-56fa18594f20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_PercentageOfAggregateAmountOfAnyOutsideFees_019d2532-c1f6-7078-814f-b24e6439a54f" xlink:href="suns-20260331.xsd#suns_PercentageOfAggregateAmountOfAnyOutsideFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_suns_PercentageOfAggregateAmountOfAnyOutsideFees_019d2532-c1f6-7078-814f-b24e6439a54f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeeExpense_019d2532-c2bc-7e7f-b107-14357683992e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_ManagementFeeExpense_019d2532-c2bc-7e7f-b107-14357683992e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncentiveFeeExpense_019d2532-c2bc-7e30-892f-3af28d81eae1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncentiveFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_IncentiveFeeExpense_019d2532-c2bc-7e30-892f-3af28d81eae1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeePayable_019d2532-c2bc-78cf-a080-08548fce0834" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_ManagementFeePayable_019d2532-c2bc-78cf-a080-08548fce0834" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableTradeCurrentAndNoncurrent_019d2532-c2bc-70b8-8518-c4cf8bf1a68a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableTradeCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_AccountsPayableTradeCurrentAndNoncurrent_019d2532-c2bc-70b8-8518-c4cf8bf1a68a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_NumberOfCoInvestedLoansHeld_019d2532-c2bc-7882-94ab-8008a7aa9595" xlink:href="suns-20260331.xsd#suns_NumberOfCoInvestedLoansHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_suns_NumberOfCoInvestedLoansHeld_019d2532-c2bc-7882-94ab-8008a7aa9595" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest_019d2532-c2bc-7fb9-8926-76e23e9ff5e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c1f6-72a6-9fed-4495c8e3b11c" xlink:to="loc_us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest_019d2532-c2bc-7fb9-8926-76e23e9ff5e0" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/RELATEDPARTYTRANSACTIONSScheduleofRelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#RELATEDPARTYTRANSACTIONSScheduleofRelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/RELATEDPARTYTRANSACTIONSScheduleofRelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c2bc-79b4-b90c-820c4f4159fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c2bc-79b4-b90c-820c4f4159fe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c2bc-75c7-acda-727daed55568" 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_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019d2532-c2bc-79b4-b90c-820c4f4159fe" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019d2532-c2bc-75c7-acda-727daed55568" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c2bc-75c7-acda-727daed55568_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_019d2532-c2bc-75c7-acda-727daed55568" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c2bc-75c7-acda-727daed55568_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019d2532-c2bc-7d0d-b4dd-471ef22b36af" 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_019d2532-c2bc-75c7-acda-727daed55568" xlink:to="loc_us-gaap_RelatedPartyDomain_019d2532-c2bc-7d0d-b4dd-471ef22b36af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019d2532-c2bc-725d-9034-82a58b8b4a8d" 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_019d2532-c2bc-7d0d-b4dd-471ef22b36af" xlink:to="loc_us-gaap_RelatedPartyMember_019d2532-c2bc-725d-9034-82a58b8b4a8d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeeExpense_019d2532-c2bc-7003-a687-6a6c992f3b52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_ManagementFeeExpense_019d2532-c2bc-7003-a687-6a6c992f3b52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncentiveFeeExpense_019d2532-c2bc-7638-bdd9-8994aa33f7ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncentiveFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_IncentiveFeeExpense_019d2532-c2bc-7638-bdd9-8994aa33f7ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019d2532-c2bc-7157-93d9-5a6da52486d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019d2532-c2bc-7157-93d9-5a6da52486d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019d2532-c2bc-744f-aad6-c2a4c24c14d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_ProfessionalFees_019d2532-c2bc-744f-aad6-c2a4c24c14d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019d2532-c2bc-7305-bd55-0ab1ed4151a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019d2532-c2bc-79d3-b33d-eac1a7f52ea6" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019d2532-c2bc-7305-bd55-0ab1ed4151a9" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/REPORTABLESEGMENTSDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#REPORTABLESEGMENTSDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/REPORTABLESEGMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019d2532-c2bc-7923-858e-37d4368f2635" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019d2532-c2bc-7923-858e-37d4368f2635" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019d2532-c2bc-76ec-a298-06b70fcc41ae" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019d2532-c2bc-7923-858e-37d4368f2635" xlink:to="loc_srt_MajorCustomersAxis_019d2532-c2bc-76ec-a298-06b70fcc41ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-76ec-a298-06b70fcc41ae_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019d2532-c2bc-76ec-a298-06b70fcc41ae" xlink:to="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-76ec-a298-06b70fcc41ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-7259-88a3-a815c1bdbac6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019d2532-c2bc-76ec-a298-06b70fcc41ae" xlink:to="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-7259-88a3-a815c1bdbac6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_TwoBorrowersMember_019dc326-8f38-7924-859a-956f8b9f708a" xlink:href="suns-20260331.xsd#suns_TwoBorrowersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-7259-88a3-a815c1bdbac6" xlink:to="loc_suns_TwoBorrowersMember_019dc326-8f38-7924-859a-956f8b9f708a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_FiveBorrowersMember_019d6264-96b6-77d6-98bf-a888e9c145dc" xlink:href="suns-20260331.xsd#suns_FiveBorrowersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019d2532-c2bc-7259-88a3-a815c1bdbac6" xlink:to="loc_suns_FiveBorrowersMember_019d6264-96b6-77d6-98bf-a888e9c145dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2532-c2bc-7c08-be0f-5c20317b0977" 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_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019d2532-c2bc-7923-858e-37d4368f2635" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019d2532-c2bc-7c08-be0f-5c20317b0977" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2532-c2bc-7c08-be0f-5c20317b0977_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_019d2532-c2bc-7c08-be0f-5c20317b0977" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2532-c2bc-7c08-be0f-5c20317b0977_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2532-c2bc-708b-b919-af2f7a67d743" 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_019d2532-c2bc-7c08-be0f-5c20317b0977" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2532-c2bc-708b-b919-af2f7a67d743" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_019d2532-c2bc-770a-97a9-9d11b7680735" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019d2532-c2bc-708b-b919-af2f7a67d743" xlink:to="loc_us-gaap_SalesRevenueNetMember_019d2532-c2bc-770a-97a9-9d11b7680735" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2532-c2bc-717e-9f67-2119c8981066" 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_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019d2532-c2bc-7923-858e-37d4368f2635" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019d2532-c2bc-717e-9f67-2119c8981066" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2532-c2bc-717e-9f67-2119c8981066_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_019d2532-c2bc-717e-9f67-2119c8981066" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2532-c2bc-717e-9f67-2119c8981066_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019d2532-c2bc-786c-9008-b2be5eb5709b" 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_019d2532-c2bc-717e-9f67-2119c8981066" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019d2532-c2bc-786c-9008-b2be5eb5709b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_019d2532-c2bc-784c-9307-a32d329ba981" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019d2532-c2bc-786c-9008-b2be5eb5709b" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_019d2532-c2bc-784c-9307-a32d329ba981" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019d2532-c2bc-7fbf-9c0c-e584e5557148" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:to="loc_us-gaap_NumberOfReportableSegments_019d2532-c2bc-7fbf-9c0c-e584e5557148" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_019d2532-c2bc-733f-bf84-d5e5cce85a7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:to="loc_us-gaap_NumberOfOperatingSegments_019d2532-c2bc-733f-bf84-d5e5cce85a7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019d2532-c2bc-7018-b12a-781a9a2ecf97" 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_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019d2532-c2bc-7018-b12a-781a9a2ecf97" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019d2532-c2bc-7595-ab13-e09f4ec747fa" 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_EntityWideInformationRevenueFromExternalCustomerLineItems_019d2532-c2bc-786a-a677-319d46d65ccf" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019d2532-c2bc-7595-ab13-e09f4ec747fa" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ir.sunriserealtytrust.com/role/SUBSEQUENTEVENTSDetails" xlink:type="simple" xlink:href="suns-20260331.xsd#SUBSEQUENTEVENTSDetails"/>
  <link:definitionLink xlink:role="http://ir.sunriserealtytrust.com/role/SUBSEQUENTEVENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019df240-d4e0-7e36-9ef0-b7be288f7d94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019df240-d4e0-7800-9668-75aaa4efeead" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019df240-d4e0-7e36-9ef0-b7be288f7d94" xlink:to="loc_us-gaap_SubsequentEventTable_019df240-d4e0-7800-9668-75aaa4efeead" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019df240-d4e0-7b98-b562-252d678349b6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019df240-d4e0-7800-9668-75aaa4efeead" xlink:to="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019df240-d4e0-7b98-b562-252d678349b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019df240-d4e0-7b98-b562-252d678349b6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019df240-d4e0-7b98-b562-252d678349b6" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019df240-d4e0-7b98-b562-252d678349b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019df240-d4e0-7db2-86d8-be5e141fdea0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MortgageLoansOnRealEstateNamePropertyTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis_019df240-d4e0-7b98-b562-252d678349b6" xlink:to="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019df240-d4e0-7db2-86d8-be5e141fdea0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_suns_ResidentialMember_019df240-d4e0-7c4a-9f12-da2b8951727c" xlink:href="suns-20260331.xsd#suns_ResidentialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_MortgageLoansOnRealEstateNamePropertyTypeDomain_019df240-d4e0-7db2-86d8-be5e141fdea0" xlink:to="loc_suns_ResidentialMember_019df240-d4e0-7c4a-9f12-da2b8951727c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019df240-d4e0-70c0-a74e-c25a4be80df6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019df240-d4e0-7800-9668-75aaa4efeead" xlink:to="loc_srt_StatementGeographicalAxis_019df240-d4e0-70c0-a74e-c25a4be80df6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019df240-d4e0-70c0-a74e-c25a4be80df6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019df240-d4e0-70c0-a74e-c25a4be80df6" xlink:to="loc_srt_SegmentGeographicalDomain_019df240-d4e0-70c0-a74e-c25a4be80df6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019df240-d4e0-7a63-9496-7b6ac096691c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019df240-d4e0-70c0-a74e-c25a4be80df6" xlink:to="loc_srt_SegmentGeographicalDomain_019df240-d4e0-7a63-9496-7b6ac096691c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_TX_019df240-d4e0-7f7b-9b12-19e0fbe27639" xlink:href="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd#stpr_TX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019df240-d4e0-7a63-9496-7b6ac096691c" xlink:to="loc_stpr_TX_019df240-d4e0-7f7b-9b12-19e0fbe27639" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019df240-d4e0-7b85-b93b-acef99dd19be" 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_SubsequentEventTable_019df240-d4e0-7800-9668-75aaa4efeead" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019df240-d4e0-7b85-b93b-acef99dd19be" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019df240-d4e0-7b85-b93b-acef99dd19be_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_019df240-d4e0-7b85-b93b-acef99dd19be" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019df240-d4e0-7b85-b93b-acef99dd19be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019df240-d4e0-7850-9c06-9bb2bab16b12" 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_019df240-d4e0-7b85-b93b-acef99dd19be" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019df240-d4e0-7850-9c06-9bb2bab16b12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019df240-d4e0-7e31-949b-c5b6bcbd38bb" 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_019df240-d4e0-7850-9c06-9bb2bab16b12" xlink:to="loc_us-gaap_SubsequentEventMember_019df240-d4e0-7e31-949b-c5b6bcbd38bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019df240-d4e0-7c64-9a58-d933f89e0594" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivableWithImputedInterestFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019df240-d4e0-7e36-9ef0-b7be288f7d94" xlink:to="loc_us-gaap_ReceivableWithImputedInterestFaceAmount_019df240-d4e0-7c64-9a58-d933f89e0594" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
