A gob of thick phlegm, spit by a consumptive man; in law Latin, UNUM VIRIDUM GOBBUM
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
oyes * p’sNathan Bailey's 1721 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes