Definitions by Joe Max

Chum 

Leftover fecal after a partial toilet flush.
Fecal left in a toilet for the purpose of grossing out the next user, generally in a public facility or done due to lack of home training.

"That nasty bastard chummed the toilet"

"Nothing worse than walking into the bathroom and seeing toilet chum!"

Chum by Joe Max May 22, 2010