RAT-A-TAT Meaning of RAT-A-TAT in English ˌrat-a-ˈtat BrE AmE ( also ˌrat-a-tat-ˈtat ) noun [singular] [ Date: 1600-1700 ; Origin: From the sound ] the sound of knocking, especially on a door Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012