Entry 1 sense Webster, 1913 Mutualism /myo͞och'-o͞o-ŭlˌ-ĭzˌ-əm/ · Mu·tu·al·ism · IPA /ˈmju.t͡ʃu.əˌlɪz.m̩/ 01 n. The doctrine of mutual dependence as the condition of individual and social welfare. 1. The doctrine of mutual dependence as the condition of individual and social welfare.(Ethics)