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
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
the act of deficating in the water tank of someones restroom, so when they flush, out comes muddy madness
by darby krow February 03, 2010
Valerie was so drunk she did an upper decker in her friends toilet at the party, and everyone smelt it.
by valere March 14, 2008
After I caught an upper decker at Busch Stadium, I went to Dan's house where I left a beefy sewer pickle in the tank of his toilet.
by porknut August 11, 2005
To take a shit in the top of the toilet, therefore when the toilet is flushed, brown water washes the poop down.
by chops renfer August 22, 2006
by Russ151 October 20, 2006