upper decker
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
The prank of defecating in the cistern of a toilet, so that flushing the toilet brings in dirty water instead of clean.
Register: slang
Where it’s used:
Used
American English
Examples
Had he been doing “upper deckers” for years in his community?
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “upper decker” mean?
The prank of defecating in the cistern of a toilet, so that flushing the toilet brings in dirty water instead of clean.
Is “upper decker” formal or informal?
upper decker is generally slang.