1. The accumulation of feces that has then solidified at the back of the toilet bowl and or toilet seat resulting in a "crust" like feature. This is usually a result of late model toilets where the diameter of the bowl is to small for the seated individual.
2. Residual food particulates and or mouth prints around the "rim" of a glass after having been put through a dish washing cycle.
3. The accumulation of feces in the hair around the anus of a "Lap dog"
1. I couldn't use the truck stop restroom because of how bad the "rimcrust" was.
2. There was "rimcrust" on a glass I wanted to use because someone did not wash the glass before putting it into the dishwasher.
3. Don't let Sally's dog sit in your lap or you'll get brown rings from the "rimcrust" on it's butt.