As you note, the word doniker, or donniker, or donnicker, is slang
word from the Circus or Carnival meaning toilet. There are many
?Carny? slang sites which state this, but only one offers an
"Carny Lingo -
Donniker ? A rest room or toilet. Possibly derived from the need to
pull down one's knickers in the outhouse. In Australian slang today,
an outhouse is a ?dunny?."
Unfortunately the author does not attribute the information.
However, the word originates from an old English word.
A search of Merriam-Webster dictionary gives the etymology as a
alteration of an old English word Dunnekin ? a toilet or cesspool ?
and first records it in 1931.
"Main Entry: donĚnickĚer
Variant(s): or donĚniĚker /'dń-ni-k&r/
Etymology: alteration of English dialect dunnekin toilet, cesspool
Date: circa 1931"
On their word for the wise page for 7 May 1999, they discuss the
various words for toilet ?
...."One less well-known synonym of toilet is donnicker, which is an
alteration of the British dialect word dunnekin, meaning ?toilet? or
Interestingly, the Australian term was first recorded at about this time -
"The Australian term 'dunny' was coined in 1933 and comes from the
British word dunnekin or 'dung house'."
- From another discussion on the origin of names for the toilet!
The word dunnekin appears in a Birmingham dialect dictionary and its
first use is noted as about 1894.
The accent in Birmingham in the Midlands of England is known as ?Brummie?.
"dunnekin n. a toilet (Northall, 1894)."
The Encarta dictionary places its origin as late 18th century.
"dunĚnaĚkin [ d˙nn?kin ] (plural dunĚnaĚkins)
U.K. construction toilet: a toilet, especially an outside one without
plumbing ( regional )
[Late 18th century. Origin uncertain: perhaps coined from dung.]"
Well this has been an interesting look at toilet names! I hope this
answers your question. If it does not, or the answer is unclear, then
please ask for clarification of this research before rating the
answer. I shall respond to the clarification request as soon as I