sambo (n.1)

"person of mixed blood in America and Asia," 1748, perhaps from Spanish zambo "bandy-legged," which is probably from Latin scambus "bow-legged," from Greek skambos "bow-legged, crooked, bent." The word was used variously in different regions to indicate some mixture of African, European, and Indian blood; common senses were "child of black and Indian parentage" and "offspring of a black and a mulatto."

a stereotypical name for male black person (now only derogatory), 1818, American English, and probably a different word from sambo (n.1); like many such words (Cuffy, Rastus, etc.) a common personal name among U.S. blacks in the slavery days (attested by 1704 in Boston), probably from an African source, such as Foulah sambo "uncle," or a similar Hausa word meaning "second son."

It fell from polite usage about the time of World War II, eventually taking with it, after the 1970s, the once-enormously popular children's book "The Story of Little Black Sambo" by Helen Bannerman, which is about an East Indian child, and the widespread Sambo's chain of U.S. pancake-specialty restaurants (founded in 1957; the name supposedly a merge of the names of the founders, Sam Battistone and Newell "Bo" Bohnett, but the chain's decor and advertising leaned heavily on the book).