rattlesnake Any of c.30 species of venomous New World pit vipers characterized by a tail rattle of loosely connected segments of unshed skin. It ranges from Canada to South America, usually in arid regions. Most are blotched with dark diamonds, hexagons or spots on a lighter background. They feed mostly on rodents. Length: 30cm–2.5m (1–8ft). Family Viperidae. See also snake

rat·tle·snake / ˈratlˌsnāk/ • n. a heavy-bodied American pit viper (genera Crotalus and Sistrurus) with a series of horny rings on the tail that, when vibrated, produce a characteristic rattling sound as a warning.