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1 definition by Hallier

 
1.
English version of German word "Kopfnuss" (head & nut), used in teenage slang.
Unlike the headbutt it is not an attack with the head but a strike on or to the head, done by using your knuckles to strike, as if you were knocking on a door.
Also a punishment for children.
"I gave him a headnut" (beat him on the head).
by Hallier September 05, 2007