A nibbler is a girl who is a pathological serial flirt who has a sociopathic desire to gain attention from as many male counterparts as possible to fulfill some deep rooted desire.
This desire/need typically stems due to the lack of a strong male influence in their lives or traumatic heart break.
They have no intention to develop a relationship or make any type of commitment with the opposite sex. Any encounter should be considered a game.
That girl at the party (the nibbler) who flirts with everyone, yet makes them all feel special. Your pretty confident your going to get some and reel her in, but all she does is nibble and keep you waiting forcing you into a downward spiral of frustration and anger.