ack-ack

== English == === Etymology === From ack (“A”) + ack (“A”), RAF WWI signalese for AA (“anti-aircraft”). (In modern signalese it would be called alpha-alpha.) === Noun === ack-ack (countable and uncountable, plural ack-acks) (military slang) Antiaircraft artillery. (military slang, uncountable) Antiaircraft fire. ==== Synonyms ==== (anti-aircraft gun): AAA, AA === References === “ack-ack”, in OneLook Dictionary Search. ack-ack on Wikipedia.Wikipedia