RATTLER Meaning of RATTLER in English /rat"leuhr/ , n.1. a rattlesnake. 2. a person or thing that rattles. 3. Informal. a fast freight train. [ 1400-50; late ME; see RATTLE 1 , -ER 1 ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012