Serpentine

1. A mineral or rock consisting chiefly of the hydrous silicate of magnesia. It is usually of an obscure green color, often with a spotted or mottled appearance resembling a serpent's skin. Precious, or noble, serpentine is translucent and of a rich oil-green color.
2. To serpentize.
3. A kind of ancient cannon.
4. Resembling a serpent; having the shape or qualities of a serpent; subtle; winding or turning one way and the other, like a moving serpent; anfractuous; meandering; sinuous; zigzag; as, serpentine braid.