Green’s Dictionary of Slang

bumbo n.2

[bum n.1 and/or Fante bumbo, vulva, but note Efik mbumbu, rotten, putrefied, decomposed; orig. W.I. use, where the term is also used to mean SE alligator; thus suggesting poss. vagina dentata imagery]

1. (also bombo-red) the vagina.

J. Atkins Voyage to Guinea 60: Some Negrish Words [...] Bombo, Woman’s [Privities].
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: bumbo [...] also the negroe name for the private parts of a woman.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]Farmer & Henley Sl. and Its Analogues.
[US]J. Sayles Union Dues (1978) 237: A sailor went to the Queen of Spain, / His name was Chris Columbo [...] And every day to pave his way / He’d stick it up her bumbo.
[WI]Francis-Jackson Official Dancehall Dict. 5: Bombo-red vagina.

2. the buttocks, the anus.

[UK]E. Sellon Phoebe Kissagen n.p.: Cherry[...] was neither flogged nor pinched, but stood behind, cooling my lord’s flayed bumbo with a fan and from time to time squeezing his balls.
[UK]A. Salkey Late Emancipation of Jerry Stover (1982) 226: Black people belong in Africa, not ’ere, an’ if ’im purge the Islan’ with ’im militant rass, ’im goin’ fin’ out that ’eaven don’t stay so one bumbo.
[WI]L.E. Adams Jam. Patois 52: Bumbo: bottom backside. A common curse word.

In compounds

bumborass (adj.)

(W.I.) non-specific intensifier used as adj.

Jamaica Patwah 31 Oct. [Internet] ‘’‘Weh do bumborass you did wid mi kyar?’.