The facial hair that grows in the weeks running up to, and during, exam season. Normally due to a person's desperate need to cram as much revision into that short space of time as possible, causing them to disregard things like basic hygeine, eating properly, social events, sleep etc
Girlfriend: Wow Mark, you need a shave!
Student: Shave!? I don't have time to shave! I've got a multi-choice business AP on monday, my spanish oral wednesday afternoon not to mention my chemistry resits!
Girlfriend: So you're gonna go to class with that rediculous pubescent stubble on your face?
Student: It's my exam beard.