\E*pon"y*mous\, a. [Gr. ?; 'epi` upon, to + ? for ? name.] Relating to an eponym; giving one's name to a tribe, people, country, and the like. What becomes . . . of the Herakleid genealogy of the Spartan kings, when it is admitted that eponymous persons are to be canceled as fictions? --Grote.