shut that cunt's mouth or I'll come over there and fuckstart her head

An attempt to shut up a loud bitch who will only yell at you becuase she thinks she won't get hit/has some big boyfriend to protect her.
One of the first lines in Way Of The Gun, delivered by Ryan Phillippe to some loud-mouth cunt yelling at him from behind her boyfiend. He then punches her in the goddamn dome.