The people you band together when you are a friend. You usually plan other's demises with them and are only together because of a fight or a compromise of that sort. You aren't really trusting of each other.
Can also be used to refer to the term, cheating on ___
May also mean friends that are close and go out to have fun, used for girls in this sort.
Me and my Girl-Friends were planning the demise of our mortal enemy
He had two girl-friends at one time, when they found out he was in trouble
Me and my girl0friends were going out for coffee