To talk thick and fast, as great praters usually do, to chatter like a magpye; also to speak a foreign language. He jabbered to rne in his damned outlandish parlez vous, but I could not understand him; he chattered to me in French, or some other foreign language, but I could not understand him.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
hyp-1 * jackNathan Bailey's 1721 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes