BLUBBER,
the Mouth, I've stopt the Culls Blubber, I've stopt the Fellow's Mouth; meant either by gagging or murdering him.
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Entry taken from 1736 Canting Dictionary, by Nathan Bailey.
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Blubber in the 1811 Vulgar Tongue
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).