MR. MACKIE: No, it was worse than that.
SHEILA: The F-woid?
MR. MACKIE: Well here’s a short list of the things your kids've been saying, m’kay?
SHARON MARSH: Oh dear God!
SHEILA BROFLOVSKY: What the heck is a "rimjob"?
LIAN CARTMAN: Oh, why that’s when you put your legs behind your head and have someone lick your ass!
The surprisingly pleasurable act of licking or having ones own sphincter licked.
The process of performing a Rim Job can be fraught with dangers such as stumbling across clingons, the rimee releasing an air biscuit, or simply encountering a particularly unhygienic ring piece.