Entry 1 sense Webster, 1913 Eponymy /ĕp-ôn'-ĭm-ēˌ/ · E·pon·y·my · IPA /ɛpˈɔnɪmˌiː/ 01 n. The derivation of the name of a race, tribe, etc., from that of a fabulous hero, progenitor, etc. 1. The derivation of the name of a race, tribe, etc., from that of a fabulous hero, progenitor, etc.