A phrase which indicates that a person is a bit of an airhead or ditzy. Also used to label a person when they are known for saying or doing stupid things on multiple occasions.
Boy 1: Hey, do you know anything about that new girl?
Boy 2: Oh yeah, that's Rebecca. Yeah, I wouldn't go for her bro. I heard she's a little blonde.
Boy 1: Oh, really? What does she do?
Boy 2: Well the other day someone told her if she scratched their back, they would scratch hers. She started scratching their back and said "Oh goodie! I've had this really bad itch all day!"
Boy 1: Wow, she is a little blonde!