Idioms and Phrases with rap someone's knuckles
rap someone's knuckles
Reprimand, as in If I'd seen John take that last piece of cake, I'd have rapped his knuckles. This term transfers a physical punishment to a verbal one. [Late 1600s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.