terminus (n.)
1550s, "goal, end, final point," from Latin terminus (plural termini) "end, boundary line," from PIE *ter-men-, from root *ter-, base of words meaning "peg, post, boundary, marker, goal" (cognates: Sanskrit tarati "passes over, crosses over," tarantah "sea;" Hittite tarmaizzi "he limits;" Greek terma "boundary, end, limit;" Gothic þairh, Old English þurh "through;" Old English þyrel "hole;" Old Norse þrömr "edge, chip, splinter").

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.