Origin of coetaneousClassical Latin coaetaneus from co-, with + aetas, age
Of equal age, duration, or period; coeval.
Origin of coetaneousFrom Late Latin coaetāneus a contemporary Latin co- co- Latin aetās age ; see aiw- in Indo-European roots.
(comparative more coetaneous, superlative most coetaneous)
From Late Latin coaetaneus (“one of the same age”).