Where does “upper decker” come from?

upper decker (English) comes from English deck, from Middle English dekke, from Middle Dutch dec, from Middle Dutch decken, from Old Dutch thecken, from Proto-West Germanic þakkjan, from Proto-Germanic þakjaną, from Proto-Germanic þaką — to cover; pole, stick, beam.

upper decker (English): The prank of defecating in the cistern of a toilet, so that flushing the toilet brings in dirty water instead of clean

Definitions

  1. The prank of defecating in the cistern of a toilet, so that flushing the toilet brings in dirty water instead of clean

Ancestry of “upper decker”, step by step

upper decker traces back through two separate lines of ancestry.

via English deck

StepLanguageWordMeaning
1EnglishdeckAny raised flat surface that can be walked on: a...
2Middle Englishdekke
3Middle Dutchdecroof, covering
4Middle Dutchdeckento roof, to build/repair a roof; to cover; to...
5Old Dutchtheckento cover; to roof
6Proto-West Germanicþakkjanto cover; to burn
7Proto-Germanicþakjanąto cover; to burn
8Proto-Germanicþakąroof, cover
9Proto-Indo-European(s)teg-to cover; pole, stick, beam

via English upper

StepLanguageWordMeaning
1EnglishupperAt a higher level, rank or position; Situated on...
2Middle Englishupper
Every word from Proto-Indo-European (s)teg-