Someone who is overly obsessed with correcting everyone's grammar. Usually to the point of obnoxious, pretentious bitchiness.
"I get sick and tired of the Walmart chick saying "May I help whose next?" every time I go to Walmart.", said the grammar bitch. And at the same time she screams at you for saying you feel good instead of well.
One who is obsessed with correcting grammar to the point of bitchiness.
A grammar bitch may point out that in the last post, "whose" should have been "who's" because it was most certainly not possessive.