Upperdeck 

When you remove the upper lid of the toilet and shit in the tank.

Tommy shammed Bobby last night. So tonight Bobbys giving Tommy an upperdeck!

Upperdeck by Squeegie Bandit May 22, 2008

Upperdeck 

An amazing band that plays christian melodic metalcore!!!

"Dude! i goin to see this freakin awesome band tonight called upperdeck!!"

Upperdeck by upperdeck... January 21, 2009

upperdecker 007

The act of taking a shit on wax paper, wrapping it up and putting it in the freezer until solid frozen. Then using the frozen turd as a time delay shit bomb, drop it in the upper tank of a toilette. The Shit Agent will have time to escape and the results won’t happen until hours after he is long gone. Once the shit thaws and someone flushes the toilette, it will fill the bowl with brown water and mission is complete.

I was over Jill’s house and she had a couple people over . I wanted to upperdecker her toilette but didn’t want to get caught. Since I have mad spy skills I used some frozen shit I stashed in her deep freezer and upperdecker 007’d her toilette , giving me plenty of time between the time I left and when Allyson went in and flushed it.

upperdecker 007 by Stephen Roche October 23, 2017

Upper Deck Deluxe

Where you do a standard Upper Decker (take a dump into the Upper toilet tank), BUT you have disconnected the chain beforehand so that some poor sap has to reach into your poop soup to even flush it.

That bitch pissed me off so bad, I got her back with a full upper decker deluxe so she'd have full shit hands after fixing it.

Upper Deck Deluxe by Ed Bodine September 11, 2005

upperdecker 

An upperdecker is when you poop in the toilet tank of someones bathroom, its the gift that keeps on giving

i was at this party and they tried to kick me out so i gave them an upperdecker

upperdecker by Nick June 18, 2006

Upperdecking 

Removing the lid of the back of someone's toilet and shitting in the clean water. Results in shit running into the boil with every flush

That bitch pissed me off, so I upperdecked her shitter

Upperdecking by Dan April 5, 2004

underdecking 

conspiring against an authority figure to take synchronized shits underneath said authority figure's deck. Usually performed in groups of two to five people. In extreme cases, shit burritos are fashioned with paper towels and left to be found.

Oh, no. Have you seen the kids? I hope their not underdecking us again!

underdecking by underdecked July 2, 2009