octogenarian

/ˈɑktədʒəˌnɛriən/

Other forms: octogenarians

Someone who's octogenarian is older than 80 and younger than 90. If your great-aunt is 84, she's an octogenarian.

You can use this word as an adjective or a noun for anyone who is in their eighties. Many octogenarians are grandparents. While one octogenarian might live in an assisted living residence and use a wheelchair, plenty of octogenarian folks drive their own cars and live in houses or apartments. Just like teenagers or thirty-somethings, octogenarians don't necessarily have much in common with each other aside from their age.

Definitions of octogenarian

1. adjective

   being from 80 to 89 years old
   synonyms:

   old

   (used especially of persons) having lived for a relatively long time or attained a specific age
2. noun

   someone whose age is in the eighties
   type of:

   golden ager, old person, oldster, senior citizen

   an elderly person