ack-ack vs antiaircraft

ack-ack and antiaircraft both are nouns.

Word	Noun	Adjective	Verb	Adverb
ack-ack	Yes	No	No	No
antiaircraft	Yes	Yes	No	No

As nouns, ack-ack and antiaircraft are synonyms defined as:

ack-ack and antiaircraft: artillery designed to shoot upward at airplanes

Other synonyms of ack-ack include ack-ack gun, antiaircraft gun, flack, flak, pom-pom.

ack-ack (noun)	antiaircraft (noun)
artillery designed to shoot upward at airplanes	artillery designed to shoot upward at airplanes

ack-ack (adjective)	antiaircraft (adjective)
	designed for defense from a surface position against air attack