1. One who is an english fiend; a language whore; a lover of intellectual intercourse.
2. Someone who knows little things like the differences between your and you're.
3. Preferably a female who knows how to construct not only proper sentences, but has a bit of wit and quirkiness within their writings; may be used to describe males who have the same ability.
1-I am a grammar queen.
2-She makes such a big deal between to, too, and two...what a grammar queen.
3-He gave me an F! Ugh! That--that--GRAMMAR QUEEN!