Another way of calling a girl a sidechick. When ordering food at a restaurant such as Popeyes or KFC you can order biscuits as a side.
Davon: Aye that girl over there fine.
Jared: What about Gretchen ?
Davon: Gretchen my main but Sophie can still be my biscuit.
Jared: You right, You right!!!
side Chick} Biscuit