An acronym standing for Group Poop. Much like women and their periods, when men begin living together, their poop cycles coordinate. A group poop is when these strapping
young whipper-snappers, members of a team, or other cohesive
unit, as it were, congregate to poop together in the same facilities. While defecating, they listen to the collective bowel calisthenics and engage in witty banter or bathroom games (i.e. kicking open the stall
door/paper towel bombings). Also
see P.I.A.G..