knock it off

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.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.