What makes a Glee fan a real GLEEK?

By knowing the charcters backrounds and just by singing and loving the show

I think what makes a glee fan a Gleek is if you talk about the couples you ship ,and listen to their covers a lot, and having suviners from the show.

Knowing the characters background singing the songs

By not just watching Glee, but identifying with the characters, and the story, and it inspires you.