Expressing distaste, alarm, or trepidation.(interjection)
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Use "ack" in a sentence
"Yes, please go see Kiki - it is very good, even in English ack! but if you can't get the sub, the dub is not the worst."
"Nicholas Baker of Louisville, Kentucky, called that classification into question, suggesting that the origin of ack-ack is German acht acht ` 8.8, 'from the designation for the weapon by its bore diameter in centimeters."
"I do not know if there is any connection between this and the British term ack-ack."