When in a crowded and loud area (party, line, etc.) and someone nearby is extremely disliked, three or more people sync their farts and release simultaneously, butts facing the person.
This chick was trying to get with my guy so my friends and I stood in front of her while she was sitting on the couch and gangfarted her in the face.
can mean anything depending on the situation and context its used in. It is a indefinable and random slogan that can be used at the end of any sentence or instead of other words to make the meaning obscure. its origins have been linked to a group of social mishaps in the hurstville metropolitan area.
whats doing gangface! meaning whats doen bro?
she was gangface of blond! meaning some blond slut