Green’s Dictionary of Slang

(US) a derog. term for a black person; also attrib.

1887		Fort Worth Dly Gaz. (TX) 9 Sept. 8/2: William Drew, alias ‘Zulu’, a well known colored character, caught a fine of £25 for aggravated assault.
1899		Irving Jones ‘I Want a Filipino Man’ 🎵 You can hear the gals declaring, Ain’t that Zulu swell.
1904		Princeton Union (NJ) 24 Mar. 4/2: We supposed the North Star State was a white man’s country [...] but according to the Union [...] we may be Zulus, Niggers or any other old thing.
1916		Day Book (Chicago) 19 Dec. 11/2: Jimmy Wilde [...] knocked out Zulu Kid of New York.
1931		G. Milburn ‘Convicts’ Jargon’ in AS VI:6 442: zoolo, n. A negro.
1944		Mencken ‘Designations for Colored Folk’ in AS XIX:3 174: The DAE does not list such vulgar synonyms for Negro as [...] Zulu.
1958		A. Sillitoe Sat. Night and Sun. Morning 166: I’m not going to freeze to death running around after a Zulu.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 110: When I’ve done me zulus, I can do about 15 sheilahs by tea time.
1978		W. Donaldson Balloons in Black Bag 90: If the Major calls him darky, [...] jungle bunny, skunk or Zulu to his face, we’re going to be short of a valuable new comedy act.
1987		C. Hiaasen Double Whammy (1990) 107: [The] enlightened citizenry, most of whom insisted on addressing him [i.e. a black highway patrolman] as Boy or Son or Officer Zulu.
1992		Bentley & Corbett Prison Sl. 56: Zulu A black person.
2002		J. Lerner You Got Nothing Coming 219: Skell pulls out a length of hollow pipe that has been flattened and sharpened like a spear. ‘Good for your Zulu uprising, dawg, know what I’m sayin’?’.
2009		J. Stahl Pain Killers 39: A young Zulu out to make his bones [...] stuck a spork in his aorta.