Making Light:  Open thread 144 ::: August 05, 2010, 11:12 AM

ddb@257 -- I suspect that the term jack to mean ice distillation is
a back-formation.  Applejack has been around since the early 1800s,
while this sense of jack seems to be a recent invention.  Even the
sense of "to lift with a jack" isn't attested until 1885.

Googling for applejack etymology, the only published hit I found
was from The Gaelic Etymology of the Languages of Western Europe*
by Charles MacKay, LL.D., 1877.  He claims that the -jack is from
Gaelic deoch, meaning "drink".
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* Or, in full, The Gaelic Etymology of the Languages of Western
Europe and More Especially of the English and Lowland Scotch, and
of their Slang, Cant, and Colloquial Dialects.