What is Upperdecker?
1.
The upperdecker is a prank that you can pull on a friend or loved one, or more likely someone who deserves it. An upperdecker is defined as defecating in the upper tank of a toilet, allowing it to fester for as long as possible and sending a chilling brown residue into the bowl upon each flush.
At a party where they run out of beer one might like to leave an "upperdecker" to show their disapproval.
2.
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."
3.
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
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