A person who's got an attractive appearance but also got nothing inside his/her head and mind. Also it means a person who believes in his/her appearance too much so that the man/woman doesn't want to do stuffs like studying, reading or the other kinds of things to be intelligent.
A: Check out that girl over there! isn't she hot?
B: Oh, that girl? I met he a week ago in a club. We went to see a movie named 'pride and prejudice' later, but when we were seeing the movie she asked for what the name 'pride and prejudice' is. She didn't know it is a novel.
A: Oh, she's a beautifool.