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.