group poop. when a large group of people go to the bathroom & takes a shit at the same time. often, texting, magazine reading and talking are done while gp-ing.
(under the stall fist-bumps are also common)
Person 1: yo, wanna gp?
Person 2: let's do it man.
A GP is a girl who is not cute to the person who called them a GP. They say GP because its stands for a girl who must have a "great personality" thats why someone would date them. definitely not for their looks though.
term is coined by ant williams j.williams and C.turner from what i know
hey man look at the girl over their" "eww she is definitely a GP