c.1408, "plant reputed to contain antivenom," from O.Fr. serpentin (fem. serpentine), from L.L. serpentius "of a serpent," from L. serpentem (nom. serpens) "snake" (see serpent). As the name of a greenish mineral, attested from 1426. The adj. meaning "twisting, winding" first recorded 1615 (an earlier adj. meaning "having the evil qualities of a serpent" is recorded from 1387). The winding lake of that name in Hyde Park, London, was constructed in 1730.