Definitions for "Almack's"
assembly rooms in King Street, London, where the most exclusive private subscription balls of the ton were held each Wednesday night of the Season. To be found worthy of the privilege of buying a subscription to the Wednesday night balls, (a ticket known as a "voucher") you had to be personally known to one of the seven powerful Society hostesses who organized it. These ladies were the so-called Patronesses of Almack's, and fashionable society lived in fear of getting on the bad side of any of them. Only the creme de la creme of Society were permitted to come.
Almack's Assembly Rooms was one of the first clubs in London which welcomed both men and women. It was one of a limited number of upper class mixed-sex public social venues in the British capital in an era when the most important venues for the hectic social season were the grand houses of the aristocracy.