The story
- Proto-Indo-European*h₁ep-
- Proto-Indo-European*h₁éps
- Proto-Indo-European*h₁épi
- Proto-Hellenic*epí
- Ancient Greekἐπί (epí)
- Ancient Greekὄνυμα (ónuma)
- Ancient Greekἐπώνυμος (epṓnumos)
- Latinepōnymu
- Frenchéponyme
- English todayeponym
Borrowed from French éponyme (“eponymous person”), from the nominalization of the adjective éponyme (“eponymous”), from Latin epōnymus (adjective), from Ancient Greek ἐπώνῠμος (epṓnŭmos, adjective), from ἐπί (epí, “upon, epi-”) + ὄνυμα (ónuma, “name”) + -ος (-os, suffix forming compound adjectives (often nominalizable)). By surface analysis, epi- + -onym.
Etymology from Wiktionary, CC BY-SA 4.0.