A man and woman sleeping in the same bed, he with his small clothes, and she with her petticoats on; an expedient practised in America on a scarcity of beds, where, on such an occasion, husbands and parents frequently permitted travellers to bundle with their wives and daughters. This custom is now abolished. See Duke of Rochefoucalt’s Travels in America.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Bun * Bung upwardsNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes