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general::
Quit or stop doing something, as in Knock it off, boys! That's enough noise. This term is often used as an imperative. [Colloquial; c. 1900] Also see KNOCK OFF.
American Heritage Idioms
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Phrase(s): Knock it off!
Inf. Be quiet!; Stop that noise! Stop doing that! • John: Hey, you guys! Knock it off! Bob: Sorry. Bill: Sorry. I guess we got a little carried away. • Sue: All right. Knock it off! Bill: Yeah. Let’s get down to business.
McGrawhill's American Idioms And Phrasal Verbs