Upper Decker

When you take a huge dump into the water tank, hence the name upper decker.

Y'all have probably seen many more definitions and guides, but I'm gonna teach y'all how to do one even better.

1. Follow the typical steps to taking an upper decker and take all neccessary precaution to not get caught.

2. On top of shitting the most horrendous turd you can manage into the water tank, also dump in a significant quantity of high calorie food or drink (like bread, meat, highly sugary drinks, etc). This gives the microbes in the shit food to feed on, making the toilet even more nasty on top of the shit thats in there.

3. Profit

Man, that dude Jim was so mean last night. I can't wait to see the look on his face once he finds out about the Upper Decker Moldy Edition TM I did to his upstairs toilet

by PT118 May 4, 2024

Upper Decker

Chicago slang for whipping out the rumpus maximus, doing a fruity little dance with your tooter, and shitting on one's roof.

Guy 1: he did an upper decker on my roof.
Guy 2: ewww man gross. Give him a Chicago sunroof
Guy 1: yeah I will, gotta get my gut going first though. Wanna get some deep dish pizza?

by very stinchy vagina master May 29, 2024

upper decker

when u shit on the top deck of the toilet

ima leave a upper decker

by Γρεεκ φεμβοΥ November 26, 2024

Upper Decky

When someone used the back tank reservoir of a toilet instead of the bowl to defacate into.

Me and the bro both had to shit, but there was only one toilet. So we stacked it and did an Upper Decky

by Bunkjeads September 14, 2025

captain upper decker

One takes a shit in the top tank of a toilet and waits for another person to flush the toilet and watches as the water is a constant brown mess

Someone must have captain upper deckered me, cause i flushed the toilet and shit continued to flow and wouldn't go away

by TheSlippyWaffle April 13, 2015

Best Friend Upper Decker

Perform an upper decker whilst your best friend shits in the bowl part of the toilet

15+ years friendship recommended, but not requires

"Why were you both in the bathroom?"

"We just best friend upper deckered that bitch"

by Badbtchfr April 11, 2022

Upper Double Decker Down

The act of defecating in the upper tank of a toilet after the consumption and digestion of a "Double Down" sandwich from Kentucky Fried Chicken.

Todd demonstrated his contempt for health and hygiene by performing an Upper Double Decker Down.

by urbanschlager April 7, 2010