| Viper 1. (a.) Any one of numerous species of Old World venomous makes belonging to Vipera, Clotho, Daboia, and other genera of the family Viperidae. 2. (n.) A dangerous, treacherous, or malignant person. Thesaurus Entries animal, beast, cur, dog, hound, hyena, insect, mongrel, ophidian, pig, pit viper, polecat, reptile, sea snake, serpent, skunk, snake, swine, varmint, vermin, whelp, worm |