Added 10 October 2026
ack-ack
noun
noun Definition from Wiktionary (CC BY-SA). More about ack-ack at Wordnik → Where our words come from →
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Antiaircraft artillery.
The army fired upon us with ack-ack.
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Antiaircraft fire.
The bomber flew through heavy ack-ack.
Origin
From ack (“A”) + ack (“A”), RAF WWI signalese for AA (“anti-aircraft”). (In modern signalese it would be called alpha-alpha.)
From Wiktionary, via Kaikki.org (CC BY-SA)