/ Dictionary / Index A ack-ack: Meaning and Definition of Find definitions for: ack-ack Pronunciation: (ak'ak"), [key] — n. Informal. antiaircraft fire. antiaircraft arms. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ack-ack (Thesaurus) ack. ackee Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language