octogenary

Etymology
From either directly or via, from  + , from. Cognate with.

Adjective

 * 1)  Of or related to the number 80, particularly
 * : lasting or aged 80 years; 80-year-old.
 * : lasting or aged 80 years; 80-year-old.

Noun

 * : a person 80 to 89 years old.