The act of wiping the rim of a barmans bumholes sought from a bar, so as to remove the taint of rat poo that is likely on the bottle fromwhen it was left outside for storage.
verb- to derat, pronounced dee-rat
An extremely well built (with either muscle or fat) and hideous greasy individual, usually a sexual deviant. Often smell putrid due to lack of hygeine and NO lack of slimey bodily hair. The grock tends to have a immensely large penis, although there have been recorded cases of grocks with wrinkley schlaggots.
I turned in horror to see a naked grock fondling himself.
Jonah: "what is that sweating mound of blubber in that cave?"
Falcon: "keep your distance I think its a grock!"