Define bang away. bang away synonyms, bang away pronunciation, bang away translation, English dictionary definition of bang away.) n. 1. A sudden loud noise , as of an explosion. 2. A sudden loud blow or bump. 3. Informal A sudden burst of action: The campaign started off with a bang. She fell bang against the wall. directly; precisely; right: He stood bang in the middle of the flower bed. Verb phrases. bang into, to collide with; bump into: The truck skidded on the ice and banged into a parked car. bang up, to damage: A passing car banged up our fender. Idioms. bang off, Chiefly British Slang. Definition of bang - a sudden loud, sharp noise, a fringe of hair cut straight across the forehead, an act of sexual intercourse., the character '!'.