1. A sinking poop. The opposite of a Floater.
2. A poop that falls below the surface of something, usually water.
3. A poop that falls directly to the bottom of the toilet bowl, sometimes referred to as a Ghost poop.
4. A poop that is sinking; A sunken poop.
1. It was such a heavy sinker that the toilet water splashed his butt as the poop nugget ripped through the water surface. The poop split in two as it was sinking. It was a titanic poop.
2. It was a risky move to pass a turd while skinny dipping in the lake with his girlfriend, but he had no choice. Luckily, it was a sinker.