Entry 1 sense Webster, 1913 Epigenetic /ĕpˌ-əj-ən-ĕt'-ĭk/ · Ep·i·ge·net·ic · IPA /ˌɛpɪd͡ʒəˈnɛtɪk/ 01 a. Of or pertaining to the epigenesis; produced according to the theory of epigenesis. 1. Of or pertaining to the epigenesis; produced according to the theory of epigenesis.