To severely injury or mutilate one's face. I heard Tom really messed his face up in that car accident.Do you want me to mess your face up or something, pal? I said get away from us!
mess someone's face up
Sl. to beat someone about the face. The champ threatened to mess the challenger's face up.The champ broke the challenger's nose and really did mess up his face.
mess someone’s face up
tv. to beat someone around the face. (Underworld.) I had to mess his face up a little, boss, but he’s been real cooperative since then.