Grammarous - Full of grammar, so meticulous about the construction of sentences and spelling of words that it is charming and fascinatingly attractive.
Me: Did you readStacy's column in the local newspaper yesterday? shes absolutely grammarous.
A person who is willing to completely kill the momentum of intelligent discourse to moan about the location of a preposition or comma in a sentence. They usually aren't as smart as they think they are, so it's their way of interjecting something they feel has intellectual value into the conversation.
We were having a really great talk about the theory of existentialism until John the fucking grammar nazi completely ignored your compelling argument just to point out that you shouldn't use a preposition at the end of a sentence.
Someone who disregards the normal use of grammar for a more stylish and effective communication of their written message. Often times with a goal of making sure their own unique personality comes across as well.
Cheryl isn't well educated but she sure knows how to use punctuation to get her point across just as she wants you to hear it. She's a true grammarartist!