any reptile of the order ophidia; a snake, especially a large snake. see illust. under ophidia.-fig.: a subtle, treacherous, malicious person.-a species of firework having a serpentine motion as it passess through the air or along the ground.-the constellation serpens.-a bass wind instrument, of a loud and coarse tone, formerly much used in military bands, and sometimes introduced into the orchestra; -- so called from its form.-to wind like a serpent; to crook about; to meander.-to wind; to encircle.