Dictionary.com
definitions

Kit-Cat Club

or Kit-Kat Club

[kit-kat]

noun

a club of Whig wits, painters, politicians, and men of letters, including Robert Walpole, John Vanbrugh, William Congreve, Joseph Addison, Richard Steele, and Godfrey Kneller, that flourished in London between 1703 and 1720.

Origin of Kit-Cat Club

from Kit (as short for Christopher) Cat(ling), alleged to be the keeper of a pie-house where the club met (with play on kit-cat, variant of tipcat; see kit3, cat)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019