rat-tat-tat exclamation 2noun 1forms 1 exclamation2 •The sound made by knocking on a door with a hard object (such as a door knocker). •The sound made by firing an automatic machine gun. noun1 •Such a sound.Then it grew louder and more distinct - it was a clear rat-tat-tat. — 1925 formsrat-tat-tats
