A person who constantly corrects misusage of the English language regardless of the inappropriate or unnecessary timing of said correction.
A couple having drinking at a bar:

Mike: "Today was crazy. I didn't have time for lunch between meetings and I felt so nauseous."

Melissa: "You mean, 'I felt so nauseated.' "

"Whatever, Grammar Dick. I'm going to go get another beer."
by M12012015M December 3, 2015
Get the grammar dick mug.