Purser’s swipes; small beer: so termed on board the king’s ships, where it is furnished by the purser.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Swindler * Swish TailNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes