Noun
An unflushed turd that has rested calmly in a toilet bowl long enough to have developed a "halo" of discolored water.
Verb
The act of leaving such a turd, either intentionally or accidentally.
When Sally entered the stall, she gagged at sight of a sweater dog in the bowl.
The waitress finally figured out which customer was responsible for sweater dogging the men's room every Saturday morning.
Celeste hates being sweater dogged!