A group of friends (usually girls ) who are really loud and random, and who often give each other random nicknames that have nothing to do with anything, like 'Babes', 'Fish' and 'Megatron'.
P1: Whats up with those randoms?
P2: Oh, they're just a Volume Group
OR
Member of Volume Group 1: Hey Sheep!
M.O.V.G 2: Hey Camel!
Bystander: #Thinks# Must be a Volume Group...