1 definition by DRoseMVP1235
Noun: Stemming from the slang for "anti-aircraft" - A person who shoots another person's idea, thought, or feeling down.
Person 1: "How about Joe's Bar tonight?"
Person 2: "How about no?"
Person 1: "You, sir, are an Ack-ack..."
Person 2: "How about no?"
Person 1: "You, sir, are an Ack-ack..."
by DRoseMVP1235 May 3, 2011