A person that appears to be cool, but not that bright or smart.
Joe is a nice guy. he is hip, but you ask him one question about something complex, he doesn't understand. He's Def and Dumb.
POV: when you procrastinate at 3 AM for a 6 page long essay you haven't started and spam random letters on your keyboard and come up with this.
def;jlkcncasda;jkcfnweoifjnhweopicawmn
Attacking an Urban Dictionary definition with a sustained barrage of thumbs-down votes.
The definition had been selected as Word of the Day. It had earned thousands of thumbs-up votes and many fewer thumbs-down. But somebody out there was peeved. Every day they contrived to give it as many thumbs-downs as they could, usually four or five, in an act of def-bombing that only underscored the power of the definition itself.