Green’s Dictionary of Slang

bushel bubby n.

[SE bushel, a dry measure + bubby n.1 ]

a woman with large breasts.

[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]E. de la Bédollière Londres et les Anglais 313/1: bushel bubby, grosse femme.