1550s, "goal, end, final point," from Latin terminus (plural termini) "end, boundary line," from PIE root *ter-, base of words meaning "peg, post, boundary, marker goal" (cf. Sanskrit tarati "passes over, crosses over," Hittite tarmaizzi "he limits," Greek terma "boundary, end, limit"). In ancient Rome, Terminus was the name of the deity who presided over boundaries and landmarks, focus of the important Roman festival of Terminalia (held Feb. 23, the end of the old Roman year). Meaning "either end of a transportation line" is first recorded 1836.