Main Entry: oc·to·ge·nar·i·an

Pronunciation: \ˌäk-tə-jə-ˈner-ē-ən\

Function: noun

Etymology: Latin octogenarius containing eighty, from octogeni eighty each, from octoginta eighty, from octo eight + -ginta (akin to viginti twenty) — more at vigesimal

Date: 1815

: a person whose age is in the eighties

— octogenarian adjective