1. A girl (or guy for that matter i guess) who is so much of a slut the only way to define them is saying they're a Bunch of sluts mashed together
2. A small group of slutty girls who stand close together.
Didn't you know?, Christina's a slutball...
Guy1: dude look at that slutball over there
Guy2: yeah man you could probably have all 4 of them girls
Both: F***ing sluts