Main Entry: to·pon·y·my

Pronunciation: \tə-ˈpä-nə-mē, tō-\

Function: noun

Etymology: International Scientific Vocabulary, from top- + Greek onyma, onoma name — more at name

Date: 1876

: the place-names of a region or language or especially the etymological study of them

— to·pon·y·mist \-mist\ noun