the act of taking a shit in the cistern of a pub or restaurent toilet to highlight dissatisfaction at service or food standards.
causes the water flushed into the toilet to be shitty. and lets face it, who is gonna take a turd out of a cistern??? muuhahahaha
by UnCLe_MeLLoN_BaLLs April 7, 2003
the act of sneaking into a bathroom, quietly lifting the lid off of the toilet tank, taking a deuce in the tank and then replacing the lid. this causes the toilet water in the bowl to be polluted after each flush. this is usually done at a party or too someone that you despise.
heath snuck into the frat house bathroom and left an upper decker in the tank, much to the dismay of the alpha betas.
by kirk May 27, 2005
To take a crap in the tank of someone's toilet and not flush afterwards. When the next person flushes your crap comes rushing into the bowl all broken apart. A lot will clog in the top. This is mean.
by Anonymous April 11, 2003
To take a crap in the top section of one's toilet so that when it is flushed, poo water flows back into the bowl.
by King Flump April 11, 2003
The act of removing the upper lid to a home toilet. leaving an imense amount of defacation inside. the next customer will go and then flush your shit into the bowl, repeatedly.
while in ohio, the clarion hotel wouldnt give us a room because we werent 21, so ryan anson gave them an upper decker
by friend July 31, 2003
mike was really pissed that the land lord was evicting him. So he left him an upper - decker.
Jim wanted to get back at his best friend Steve for sleeping with his girlfriend, so he left him an upper - decker.
Jim wanted to get back at his best friend Steve for sleeping with his girlfriend, so he left him an upper - decker.
by TNT- DOUG September 27, 2006
The act of removing the lid off the back part of a toilet and pooping in it. Poop comes in the bowl over time after flushes. Usually done at big parties that have gone wrong.
The host of that party was so horrible that Andre couldn't resist pulling an upper decker before we left.
by Agenda July 13, 2005