A slow-festering, painful acne cyst. The zit simmers under the surface of the skin for several days while a monster zit cooks up. When it finally surfaces, the crockpot zit doesn't feed 6-8, but it will wreck havoc on the face.
Madison: Dang, I've had this zit on my forehead for like 3 days already, and it's not even a full-on zit yet!
Julian: Shit, looks like a crockpot zit. It won't be done cooking till dinnertime tommorrow."
Girl, don't try to pop that crockpot zit; you're only going to make it worse!