A thin, small, hard cider, much used by vintners and coopers in parting their wines, to lower the price of them, and to advance their gain. A freezing vintner; a vintner who balderdashes his wine.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Freeman’s Quay * French CreamNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes