Usually accompanied with a zip-up hoodie, Dickies pants and Chuck Taylor shoes.
This person's perception of the world is pessimestic and/or sarcastic. Approach with caution because he's probably a jerk and think's he's much cooler than you, square.
Johnny: "Don't worry about him. He's just a glasshole."
"Look there, under the bleachers. Some glasshole is looking up women's skirts!"
"...So the glasshole meets this girl and looks her up online, finds out everything about her, and is waiting for her in her front yard when she gets home that night. That was when she maced him and called the cops."
Guy: Hey there....Jessica? The face recognition linked me to your Facebook page and I can see you like cats...
Jessica: Don't be a Glasshole and stop stalking me