A slang term for the food served at a pub or bar. Usually it is fast food, grilled or deep fried. Sometimes it is even a frozen pizza cooked in a toaster oven. Salty popcorn is often offered as free pub grub (to encourage drinking.)

when you're hungover as shit after a spending a night drunk as a skunk

A putrid smell produced as a result of passing wind can be described as PubGrub.

Originates from the familiar odours that can be noticed when dining in a traditional English public house.

Extremely low grade cocaine, typically bought in the toilets of a manky boozer. As likely to engender feelings of paranoia and a horrible empty craving for more than any actual enjoyable buzz.