1640s, in astronomy, of a star or planet, "come to or be on the highest point of altitude; come to or be on the meridian," from Late Latin culminatus past participle of culminare "to top, to crown," from Latin culmen (genitive culminis) "top, peak, summit, roof, gable," also used figuratively, a contraction of columen "top, summit" (from PIE root *kel- (2) "to be prominent; hill"). Figurative sense in English of "reach the highest point" is from 1660s. Related: Culminant; culminated; culminating.
