One who uses refined vocabulary, correct grammar, constantly finds themselves correcting grammar and spelling (in forums, chatrooms, tumblr, YouTube, etc.)

First, you have your mild GNs, they're much kinder and respectively tell you about your grammar/spelling that is incorrect.

Then there's your experienced GN, they're much harder on you and constantly browse through pages to reply to people who have terrible grammar and spelling form.

Finally, there's the hardcore GN, only they have earned the right to sPELL liKe thisss and still be refined, respected, not a asshat GN like most internet GN are. They usually reply with a simple correction and move on.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

noun (pl. -s)
1. A person who uses proper grammar at all times, esp. online in emails, chatrooms, instant messages and webboard posts; a proponent of grammatical correctness. Often one who spells correctly as well.

2. a – A person who believes proper grammar (and spelling) should be used by everyone whenever possible. b – One who attempts to persuade or force others to use proper grammar and spelling. c – One who uses proper grammar and spelling to subtly mock or deride those who do not; an exhibitor of grammatical superiority. d – One who advocates linguistic clarity; an opponent of 1337-speak. e – One who corrects others' grammar; the spelling police.

proper noun
3. A nickname, pseudonym or handle for a well-known grammar nazi (defs. 1 and 2) within a particular social circle, used to show either great respect or great contempt for his or her abilities.

verb (transitive)
4. To correct the grammar of (a person's speech, a piece of writing, etc.); to edit for grammar and spelling; to proofread.

Someone who believes it's their duty to attempt to correct any grammar and/or spelling mistakes they observe. Usually found hanging around Irc chatrooms hounding "n00bs".

To the previous poster. It is spelled grammar, not grammer.

Someone who believes it's their duty to correct any grammar and/or spelling mistakes they observe.

A captious individual who cannot resist the urge to correct a spelling and/or grammar mistake even in informal settings. After pointing out the linguistic shortcomings in others, a Grammar Nazi feels a strange sense of twisted and unconstructive intelligentsia delight.

In reality, they are making someone else feel bad for no reason and unintentionally implying that their "superior" grammar skills are all they have to show for a wasted liberal arts education.

While proper grammar usage is all well and good, a Grammar Nazi cavils even insignificant errors in English to somehow win an argument. Of course, rather than being genuinely persuasive in an argument, pointing out English errors is a weak attack only on the typist's credibility and never has any bearing on the underlying premises and assertions therein.

In other words, this is simply a disguised ad hominem argument which intelligent and logical people disregard.

Still, one should strive to spell and use words properly, but arrogant and unsolicited advice is not a very persuasive way to teach English.