ack-ack acid yellow • ack emma · · · Info · Definitions · Synonyms · Characters · · ack-ack · · Text Common · · Latin · · Scripts 7 · · Length Definitions · · · (noun) artillery designed to shoot upward at airplanes. Synonyms: antiaircraft, antiaircraft gun, flak, flack, pom-pom, ack-ack gun. · · Noun Definition 1 Synonyms · · · antiaircraft · · Synonym 1 antiaircraft gun · · Synonym 2 flak · · Synonym 3 flack · · Synonym 4 pom-pom · · Synonym 5 ack-ack gun · · Synonym 6 Characters · · - hyphen-minus U+002D a latin small letter a U+0061 c latin small letter c U+0063 k latin small letter k U+006B