To talk. To patter flash; to speak flash, or the language used by thieves. How the blowen lushes jackey, and patters flash; how the wench drinks gin, and talks flash.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Pattering * Paviour’s WorkshopNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes