Willard Espy offers the
following explanation for kitty, the pot to which poker players
contribute, in Thou Improper, Thou Uncommon Noun (1978): "[The name]
Catherine turned to Kate, and Kate to Kitty. Some Kittys were no better than
they should be, and Kitty became one of the many epithets applied to
prostitutes. Spirited Johns - not yet lowercases for a prostitute's customer -
used to amuse themselves by tossing coins into the laps of Kittys, as poker
players today throw their antes or bets into a kitty in the hope of getting a
winning hand. The sequence cannot be proved - no one will talk - but it seems
plausible." Note that no cats are involved in this tale.