A Saturday morning shit that nasty bowel movement you often have at approximately 10:00am on a Saturday morning after a long Friday night of partying and drinking. Generally, the Saturday morning shit is induced by a large cup of coffee.
Taking, or, rather, leaving a Saturday morning shit is not a short project. Expect a twenty minute sit.
1. Dude, I can't talk right now, I'm concentrating on my Saturday morning shit.

2. Boy was that Saturday morning shit nasty. I plugged the toilet and the bathroom fan will have to run all day to evacuate the stench.
by Rook's Buddy May 10, 2010
Get the Saturday morning shit mug.