An Irish Lastname, usually the last name of a person who likes to get hammered drunk (hence the irish) and/or buckwild. Fun person!
person 1: "Look at ryan over there, hes sooo drunk!"
person 2: "dude, he's an o'dell, this is what hes sopose to do!"
very ugly person full of stupid thoughts. Usually blonde, but ocasionally brunette.
Chelsi is such an o'dell!