The story
From ack (“A”) + ack (“A”), RAF WWI signalese for AA (“anti-aircraft”). (In modern signalese it would be called alpha-alpha.)
Etymology from Wiktionary, CC BY-SA 4.0.
ack-ack
Today it means: Antiaircraft artillery. Full definition →
Today it means: Antiaircraft artillery. Full definition →
From ack (“A”) + ack (“A”), RAF WWI signalese for AA (“anti-aircraft”). (In modern signalese it would be called alpha-alpha.)
Etymology from Wiktionary, CC BY-SA 4.0.