The name that's commonly used for a certain girl named Jessica Hall. This does not necessarily mean she is a "nice girl" because of the lack of the space in between "nice" and "girl", and should not be used as in "she's a nice girl", but as in "she's Nicegirl"
It is a proper noun and has been linked with Jessica Hall for almost 3 years.
Given to her by Tyler Gunn and Nate Irvin, and some other guys that were there at the time
Nicegirl- "Hey! I got my tits signed by Dani Filth and partied all weekend!"
Guy- "I thought you were supposed to be a nice girl?"
Some other person- "Retard, her NAME is Nicegirl she's not a nice girl!"