Webster's Revised Unabridged Dictionary · 1913

Eponymous

Eponymous , adjective

[Greek {not transcribed}; 'epi` upon, to + {not transcribed} for {not transcribed} 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