1. Someone who has surpassed the levels of jerk and asshole, however not yet reached fucker or motherfucker. Not to be confused with douche.
Rob:He kept hitting on my girlfriend at the party, he just wouldnt leave her alone!!
Peter: God, what a douchebag.
2. An individual who has an over-inflated sense of self worth, compounded by a low level of intellegence, behaving ridiculously in front of colleagues with no sense of how moronic he appears.
Your boss is a real douchebag!
Just in case you forgot what a douchebag is, you can read below and make sure you nor your friends become one.