Actually I'll share the definition for everybody :
A person who believes it is their destiny to stamp out all spelling and punctuation mistakes at the cost of popularity, self-esteem and mental well-being.
They're out there. They're reading this right now. Judging, smirking, analyzing. They care nothing about the actual meaning or fun of writing, but care everything about whether you used that semi-colon correctly. While we -- perhaps inappropriately -- call them Grammar Nazis, the Finns have a much more fitting name: "pilkunnussija."
Very not nice word in that terrible article linked right after this very long sentence that is here for absolutely no reason except looking like it's very long plus because I failed rules somehow but Alvin fixed it so I think it's okay for now but we really need to carry on so I think I will carry on to finish the explanation if you can dare reading the really very not nice word of doom in said article.