rattlesnake Syllabification: (rat·tle·snake)Pronunciation: /ˈratlˌsnāk/Translate rattlesnake | into French | into German | into Italian | into Spanish Definition of rattlesnake noun a heavy-bodied American pit viper with a series of horny rings on the tail that, when vibrated, produce a characteristic rattling sound as a warning. Genera Crotalus and Sistrurus, family Viperidae: several species rattlesnake in other Oxford dictionaries Definition of rattlesnake in the British & World English dictionary