What is Knuckle Head?
1.
Someone of limited intelligence and with a mean nature. Who prefers using their knuckles/fists, to using their head.
That doorman looks a real knuckle head
2.
Someone who has just made a mistake or done something wrong. Often used in a joking manner between friends.
After arriving at the ski resort Pat discovered that he had forgot his skis to which his friends responded "Pat, you're a knuckle head!".
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