I have come to the realization that the world geule is used in jillions of expressions and is never taught in French class. Probably because it's a little rude. But really, it's used for everything. So here's the scoop.
la geule= mouth of a dog or animal, muzzle
Ways to use this word:
1. (fermer) Ta geule= (close) your geule= shut up (rude)
2. Faire la geule= to do/make the geule= give someone the silent treatment
3. Tirer la geule= to pull the guele= give the evil eye, give someone a dirty look
4. Se casser la geule= break your geule= have some kind of accident and hurt yourself, wipe out
5. Je vais te casser la geule= I'm going to break your geule= I'm gonna beat your face in
6. grande/grosse geule= big/fat geule= big mouth, noisy
7. regarde sa geule=look at his geule= look at his face/facial expression
8. Engeuler= the verb form of geule= to yell at someone
9. Avoir une geule de con=have a stupid geule= look stupid, seem stupid
10. geuler=another verb form= shouting
11. futre de la geule de quelqu'un=f--- of someone's geule=to laugh at someone
Voilà. Little slang lesson of the day.