that beyotch pissed me off, so I ate 3 large burritos, took some Ex Lax, went over to her house and left her an upper-decker to deal with.
by Amanda Huggankiss August 02, 2006
A vengeful act of defacating in the tank of a toilet so as to odorize the bathroom with every flush for weeks until found. This is usually done at parties where you don't like the host/hostess.
"everytime I flush the toilet my bathroom wreaks, someone must have left an upperdecker, when I said the parties over go home..OH man! they did."
by troy garner September 02, 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 10, 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 30, 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 10, 2003
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 07, 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 26, 2005