quinquagenarian

From Latin quinquāgēnārius (“containing 50”) + -an, either directly or via French quinquagénaire, from Latin quīnquāgēnus (“50 each”) + -ārius (“-ary”), from quīnquāgintā (“five tens, fifty”). Cognate with quinquagenary.

• (General American) IPA^(key): /ˌkwɪŋkwəd͡ʒəˈnɛɹiən/
• (Received Pronunciation) IPA^(key): /ˌkwɪŋkwəd͡ʒɪˈnɛəɹɪən/

quinquagenarian (plural quinquagenarians)

1. (obsolete, rare) Synonym of pentecoster: an officer who commands 50 men.
2. Synonym of fiftysomething: a person between 50 and 59 years old.

quinquagenarian (not comparable)

1. (obsolete, rare) Of or related to command over 50 men.
2. Of or related to fiftysomethings.

   Coordinate terms: vicenarian, tricenarian, quadragenarian, hexagenerian, sexagenarian, septuagenarian, octogenarian, nonagenarian, centenarian, supercentenarian

• semicentenarian, quinquagenary

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