n.
Pronunciation: ˌ äk-t ə -j ə - ' ner- ē - ə n
Function: noun
Etymology: Latin octogenarius containing eighty, from octogeni eighty each, from octoginta eighty, from octo eight + -ginta (akin to intransitive verb ginti twenty) ― more at VIGESIMAL
Date: 1815
: a person whose age is in the eighties
– octogenarian adjective