Defny

A girl who is incredibly attractive, intelligent, witty and charming, but extremely prone to sudden and random outbursts.
A hot spaz chick.

Wes: Hey did you see that new chick at work? She's so hot!
Joe: Yeah, I was talking to her for like 3 minutes and she suddenly started screaming about how awesome our uniforms are.
Wes: Whoa! I had no idea she was such a defny!