adjective. Used to describe gossip or jokes that whilst possibly amusing might also be considered tasteless / inappropriate / a desperately poor attempt at humour - in fact just anything that isn't bantalicious
"Did you hear what happened to Oli in Shelina's room?"
"I'm not sure I want to, if it's as bantasgusting as last time"
1. Any sexual activity, specifically that of the rough 'n' ready nature - a "quick bonk".
2. A piss-easy maths course taken by proven softies.
"Oli, what are you up to this afternoon?"
"I'm going to Matt's room to do some QB"