1.) A single woman who's only romantic feelings fall for her Gay Best
Friend
2.) Quintessentially, the wife of a gay
man.
(You may notice a hag called "Fag Hag" but, most will get offended with that little addition because it is so derrogatory and demeaning to her best
friend.)
Grace, from Will & Grace, is Will's Hag. I
mean, they are practically husband and
wife.