"jankers" antedated to 1914

[Stephen Goranson]

OED has 1916. "Etymology:  Origin unknown. Services' slang."
"Punishment for defaulters; the defaulters themselves; the cells in which they are placed. Also attrib. (occas. in sing. form)."

The British Army from Within, by Evelyn Charles Vivian (NY: George H. Doran, 1914) pages 35-38. (Not confirmed on paper, but full scan at Google Books).

http://books.google.com/books?id=GKpJAAAAIAAJ&pg=PA35&dq=jankers+-bankers&hl=en&sa=X&ei=3LFfUtmQE9Ot4AOv3YC4DA&ved=0CFwQ6AEwCTgK#v=onepage&q=jankers%20-bankers&f=false

Stephen Goranson
http://people.duke.edu/~goranson/

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