Definition of serpents:
(n) :
(now literary) A snake, especially a large or dangerous one.
(n) :
(figurative) A subtle, treacherous, malicious person.
(n) :
(mythology, fantasy) A snake-like monster, such as a dragon or sea serpent.
(n) :
(music) An obsolete wind instrument in the brass family, whose shape is suggestive of a snake (Wikipedia article).
(n) :
A kind of firework with a serpentine motion.
(v) :
(obsolete, intransitive) To wind or meander