Preferably the youngest member of a friend group, or one who acts the youngest. Used as a joking insult between friends and can be used as an insult to someone immature or inexperienced
A fat chicklying on her back ready for missionary. (E.Lincourt-2006)
In comparison to what an uncooked chicken looks like lying on the counter before it is cooked for dinner. A Big bulbous body with little arms, big thighs and the skin full of tiny goosebump-like pours where all of it's feathers have been plucked from.
Man, I got so drunk that night that I setted for an uncooked chicken!