schvartze (n.)

also schvartzer, "black person" (somewhat derogatory), 1961, Yiddish, from schvarts "black" (see swarthy). Perhaps originally a code word to refer to black servants when they were within earshot, as German cognate Schwarze appears to have been used mid-19c.:

In Baltimore in the 80s of the last century, the German-speaking householders, when they had occasion to speak of Negro servants in their presence, called them die Blaue (blues). In the 70s die Schwartze (blacks) had been used, but it was believed that the Negroes had fathomed it. [H.L. Mencken, "The American Language," Supplement I, 1945]