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.)
I never see John any more. Has he been working a lot? Working? The guy's a rub and grub. He never leaves the house and he pays for his porn accounts with his food stamp money.