Isabummer is the name given to Isabella Swan from the Twilight series referring to the way she whines and mopes. It is a play on words.
Friend 1: I didn't want presents for my birthday! I didn't want a party!
Friend 2: Keep whining about how much you hate people giving you presents and you'll turn into Isabummer!
Friend 2: Keep whining about how much you hate people giving you presents and you'll turn into Isabummer!
by BTell January 30, 2011