rap one's knuckles

[rap one's knuckles] {v. phr.} To scold or punish.

The principalrapped our knuckles for cheating on the test.

If you talk back toDad, you'll get your knuckles rapped.

The club got its knucklesrapped by the principal for hazing new members.

Why rap myknuckles? It wasn't my fault.

Compare: DRESSING DOWN, GIVE IT TO(2).