"rapid stream," c.1600, from Middle French torrent (16c.) and directly from Latin torrentem (nominative torrens) "rushing, roaring" (of streams), also "a rushing stream," originally as an adjective "roaring, boiling, burning, parching, hot, inflamed," present participle of torrere "to parch" (see terrain). Extension to any onrush (of words, feelings, etc.) first recorded 1640s.