Slang.

From John Badcock's:

Slang.
A Dictionary
of
the Turf, the Ring, the Chase, the Pit, of Bon-Ton,
and the
Varieties of Life,
Forming the Completest and Most Authentic
Lexicon Balatronicum
Hitherto Offered to the Notice of
the Sporting World,
For elucidating Words and Phrases that are necessarily, or purposely,
cramp, mutative, and unintelligible, outside their
respective Spheres.
Interspersed with
Anecdotes and Whimsies,
with Tart Quotations, and Rum-Ones;
with Examples, Proofs, and Monitory Precepts,
Useful and Proper for
Novices, Flats, and Yokels.