Pigeon French, or French as it is spoken by the coloured population of Louisiana, the French West Indies, Bourbon, and Mauritius. (Connected with jumbo.)
“Creole is almost pure French, not much more mispronounced than in some parts of France; but Gombo is a mere phonetic burlesque of French, interlarded with African words, and other words which are neither African nor French, but probably belong to the aboriginal language of the various countries to which the slaves were brought from Africa.”
—The Nineteenth Century. October, 1891, p. 576.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Gombo from Fact Monster: