octogenarian

From Latin octōgēnārius + -an (“forming adjectives and representative nouns”), either directly or via French octogénaire, from Latin octōgēnus (“80 each”) + -ārius (“-ary”), from octōgintā (“eight tens, 80”).

• (General American) IPA^(key): /ˌɑktəd͡ʒɪˈnɛɹiən/
• (Received Pronunciation) IPA^(key): /ˌɒktəd͡ʒɪˈnɛəɹɪən/

octogenarian (plural octogenarians)

1. Synonym of eightysomething: a person between 80 and 89 years old.
   • 1929, Robert Dean Frisbee, The Book of Puka-Puka (republished by Eland, 2019; p. 75f; emphasis in original):

     Mama was by no means the only grandma present, for the octogenarians had turned out en masse from their huts and lean-tos and were paddling about, diving and splashing as unconcernedly as though they really belonged in the sea rather than on land.

   • 1941 October, “Notes and News: Finsbury Park Station”, in Railway Magazine, page 466:

     Finsbury Park station, one of the most important L.N.E.R. suburban junctions, is now an octogenarian.

   • 1951, IBM Corp., Proceedings, Computation Seminar, page 13:

     To replace logarithmic tables with natural tables required some time. This seems like a modern age, yet I am not an octogenarian and I can remember the dying gasp of the logarithmic table as the standard method of computation. I have seen the desk calculator become a necessary instrument for every scientist who is doing quantitative work.

octogenarian (not comparable)

1. Of or related to eightysomethings.

   Coordinate terms: vicenarian, tricenarian, quadragenarian, quinquagenarian, semicentenarian, hexagenarian, sexagenarian, septuagenarian, nonagenarian, centenarian, semisupercentenarian, supercentenarian

• octogenary (obsolete)

• “octogenarian, n. and adj.”, in OED Online ⁠, Oxford, Oxfordshire: Oxford University Press, 2022.