Main Entry: no·na·ge·nar·i·an

Pronunciation: \ˌnō-nə-jə-ˈner-ē-ən, ˌnä-\

Function: noun

Etymology: Latin nonagenarius containing ninety, from nonageni ninety each, from nonaginta ninety, from nona- (akin to novem nine) + -ginta (akin to viginti twenty) — more at nine, vigesimal

Date: 1804

: a person whose age is in the nineties

— nonagenarian adjective