Synonyms for Antiaircraft (same or very similar meaning)
WordNet sense 1 (artillery designed to shoot upward at airplanes):
flack, flak, ack-ack, pom-pom, ack-ack gun, antiaircraft gun
WordNet sense 2 (intended or appropriate for defending against or deterring aggression or attack):
defensive
From the ODE community, based on WordNet
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