"having the same age, having lived for an equal period," 1620s, from Late Latin coaevus"of the same age," from assimilated form of Latin com "with, together" (see com-) + aevum "an age" (from PIE root *aiw- "vital force, life; long life, eternity"). As a noun from c. 1600.
coercion
coercive
coessential
coetaneous
coeternal
coeval
coevolution
coexist
coexistence
coextensive
coffee