Norwegian slang for insulting someone. 'Løk' means onion, but may be used in several ways.
din jævla løk!
erru en jævla løk eller?
The word means onion in English. Used to say that somebody is stupid or a looser.
"Look at that løk"
"He's such a løk!
"That stupidass motherfucker is a real løk-head"