knock (one's) block off(redirected from knock their blocks off)
knock (one's) block off
To strike someone with great force, usually in the head. If you insult me like that again, I'll knock your block off!
knock someone's block off
Sl. to hit someone hard in the head. Wilbur almost knocked Tom's block off by accident. He threatened to knock my block off if I didn't do as I was told.