eponym (n.)

before vowels reduced to ep-, before aspirated vowels eph-, word-forming element meaning "on, upon, above," also "in addition to; toward, among," from Greek epi "upon, at, close upon (in space or time), on the occasion of, in addition," also "after," from PIE *epi, *opi "near, at, against" (source also of Sanskrit api "also, besides;" Avestan aipi "also, to, toward;" Armenian ev "also, and;" Latin ob "toward, against, in the way of;" Oscan op, Greek opi- "behind;" Hittite appizzis "younger;" Lithuanian ap- "about, near;" Old Church Slavonic ob "on"). A productive prefix in Greek; also used in modern scientific compounds (such as epicenter).

Proto-Indo-European root meaning "name."

It forms all or part of: acronym; allonym; ananym; anonymous; antonomasia; antonym; binomial; caconym; cognomen; denominate; eponym; eponymous; heteronym; homonym; homonymous; hyponymy; ignominious; ignominy; innominable; Jerome; matronymic; metonymy; metronymic; misnomer; moniker; name; nomenclature; nominal; nominate; noun; onomastic; onomatopoeia; paronomasia; paronym; patronym; patronymic; praenomen; pronoun; pseudonym; renown; synonym; synonymy; synonymous; toponym.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nama; Avestan nama; Greek onoma, onyma; Latin nomen; Old Church Slavonic ime, genitive imene; Russian imya; Old Irish ainm; Old Welsh anu "name;" Old English nama, noma, Old High German namo, Old Norse nafn, Gothic namo "name."