Besides the common definition... A behemoth, often coiling, mass of stool that grows and grows until finally reaching above the water level of a toilet bowl. Known to be associated with binge eating. Kind of like one of those underwater volcanoes that breaks the ocean surface.
I had the munchies so bad all weekend, btw do you have a plunger I took an upper decker in your shitter and it's backed up.
by evangelicalathiest April 4, 2011
by Ann_Archy September 13, 2018
"I wasn't able to get a beer at this party, so I took it upon myself to give him an upper decker in the toilet".
by mark abestin December 18, 2003
AN ACT OF WAR. To take shit shit (some crazy how) in the upper tank of a conventional toilet. The next flush will be your shit and shit colored water. WARNING: The tank will be saturated with your shit. Hence the WAR about to commence. Do not do this without an immediate exit plan. And a fucking follow up plan of how and why you did such a fucking nasty thing.
I took and Upper Decker and dipped. Because I hate that fuck. And I am also a nasty unhygienic piece of shit whom wanted to fowl their party and embarrass.... fucking however.
by theutopianing April 18, 2012
Taking a shit in another person’s essential oil humidifier without telling them. Usually as a form of retaliation in which a classic upper decker just won’t cut the mustard.
“I know I had to get back at that twat waffle after he cheated on me with my sister. So naturally I left him a boujee upper decker when I moved out.”
by Gettin' It.... March 9, 2022
The act of defecating in the upper tank of a toilet, exhaling vape into the tank and then sealing it for a honeydew, kiwi, and cool mint surprise!
by GiantsMartyr January 21, 2018
To put toilet paper over someone elses poo when the toilet is clogged and then take a shit on top of the original poo.
by grind January 17, 2004