Spartan Mouth

the act of talking an incredible amount of shit, which you may or may not be able to back up. The point is, you just keep going no matter what.

dude1: hey broskii, did you see that chick over there on the other side of the bar?
dude2:yea man, she's here with some douche.
dude1:time to lay down the moves.
dude2:hey man, watch that spartan mouth before you get your ass kicked.