English Dictionary

rap someone's knuckles

verb

(literally) to tap one's knuckles on an object such as a desk or wall to attract attention or as a signal of commmunication. / (somewhat dated, idiomatic) to give someone a punishment.

The teacher rapped the student's knuckles with a ruler.

意味（1）

(literally) to tap one's knuckles on an object such as a desk or wall to attract attention or as a signal of commmunication.

Just rap your knuckles on the wall when you're ready to go.

意味（2）

(somewhat dated, idiomatic) to give someone a punishment.

If the sales department doesn't get organized soon, the CEO is going to rap their knuckles.

意味（3）

(archaic, literally) to strike someone on the back of the hand with an object such as a stick or ruler as a method of punishment.

In the old days the teacher would rap someone's knuckles with a ruler if they misbehaved in class.