Green’s Dictionary of Slang

(US) a short, fat person.

1793		Sporting Mag. Oct. III 54/1: There was Dorothy Dump, would mutter and mump.
1840		E. Howard Jack Ashore I 294: The artfulness of her tater-faced dump of a daughter.
1867		T. Carlyle Reminiscences II 53: The door opened and there in waddled a puffy, thickset, vulgar little dump of an old man.
1886		C. Hazard Memoirs of Rev. Diman V 94: The little dump of a rector made an eloquent address on the importance of observing the laws, and gave us the usual right hand of fellowship .
1900		E. Glyn Visits of Elizabeth 63: She is a big dump with a shiny complexion.
1967–8		Baker et al. CUSS 111: Dump An ugly person, female.