Any of a suite of dodgy meat productspurchased from a mobile eatery (e.g. a kebab van owned by a man called Stelios) often found in car parks within close proximity to nightclubs.
I feel dead rough this morning. I think it must be that filthy ratburger I got from "Kebab Ye" on the way home from "Shades" last night.
ratbassery is playing Fortnite or warzone like a pussy bitch. Hiding and camping and scurrying around without being seen. Ratbassery is an art form developed by an old friend, and adapted by many.