n. venomous semiaquatic snake (Agkistrodon piscivorus) of swamps in southern U.S.; -- called also water moccasin, cottonmouth moccasin, and cottonmouth water moccasin. It grows to a length of about 4 feet. The name refers to the whiteness of the lips and inside of the mouth.
Syn. -- water moccasin, cottonmouth moccasin, Agkistrodon piscivorus. [ WordNet 1.5 +PJC ]