1)to destroy, ruin, damage or disfigure. 2) also, to fornicate (usually violently)
ex 1. dude...i totally gnargled my knees when i ate shit bombing that hill.
ex 2. ha...bitch, i gnargled your mom
1) refering to a dirty scrotum,
can also be used as a label for a dirty person
goddamn take a shower you scrag bag