serpentine (adj.)

"twisting, winding," 1610s; see serpent + -ine (1). An earlier adjective meaning "having the evil qualities of a serpent" is recorded from late 14c., from the French source of serpentine (n.). The winding lake of that name in Hyde Park, London, was constructed in 1730.

serpentine (n.)

c. 1400, "plant reputed to contain antivenom," from Old French serpentin name of a precious stone, noun use of adjective meaning "of a snake, snake-like; sly, deceptive," from Late Latin serpentius "of a serpent," from Latin serpentem (nominative serpens) "snake" (see serpent). As the name of a greenish igneous rock consisting mainly of hydrous magnesium silicate, attested from early 15c.