Green’s Dictionary of Slang

1. (US) a striped prison uniform; also attrib.

1899		J. Flynt Tramping with Tramps 144: He got into limbo, and had to wear the famous ‘zebra’ – the penitentiary dress.
1921		P. & T. Casey Gay-cat 201: They were the black-striped, shoddy garments of a convict. ‘A zebra suit!’ breathed the Kid.
1935		A.J. Pollock Und. Speaks.

2. (US, also zebu) a convict.

1882		G.A. Sala America Revisited I 255: For awhile I was puzzled; but he went on to explain that a ‘Zebra’ was a humorous nickname for a convict.
1893		J. Hawthorne Confessions of Convict 14: Zebu, convict.
1921		P. & T. Casey Gay-cat 166: I jes’ knowed right off he was lookin’ for that zebra what had made his getaway from stir.
1929		Hostetter & Beesley It’s a Racket! 242: zebra — A convict, or criminal or racketeer who has served a prison sentence, (i.e. worn stripes.).
1940		C. Rawson Headless Lady (1987) 28: Zebras are convicts.
1949		Monteleone Criminal Sl. (rev. edn).

3. (UK black) a half-caste.

1982		R.M. Brown Southern Discomfort (1983) 124: Willy Patterson called me a zebra today [...] he said I was half white and half black.
1999		(con. 1979–80) A. Wheatle Brixton Rock (2004) 33: Calling me names like ‘mongrel’ and ‘zebra.’.
2006		C. Carr Our Town 94: Them half-breed babies running around, which I call zebras.

4. (US, also zebe) a stripe-shirted sports umpire.

1972		D. Jenkins Semi-Tough 231: Who I worry about, mainly, in pro football are the zebras. The officials.
1984		D. Jenkins Life Its Ownself (1985) 87: Offensive holding [...] was something a zebra called when it was time to fuck you out of your bet but win him his. [Ibid.] ‘Who’s your favorite zebe these days?’.
1996		Eble Sl. and Sociability 19: Basketball fans might call ‘an official’ a zebra.
2006		F.X. Toole Pound for Pound 56: If Eloy thought the referees had made a bad call, he’d rumble [...] ‘Yessir, somebody got to the zebras.’.

5. (US black teen) a white person who poses as black.

2004

Urban Dict. 9 Mar.

6. (N.Z. drugs/prison) a dose of LSD; the drugs has been impreganted into a small piece of blotting paper.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 206/1: zebra n. an LSD tab [...] there are a multitude of names for LSD depending on the design on the paper. Some reported examples include: Asterix; baldheaded lesbian; Bart Simpson; Batman, blue Om (an Arabic symbol); Bob Marley; buddha (a tab produced in several different colours); clear light; clown face; dollars and cents; double dip (where the blotting paper is dipped twice in the LSD mixture); dot; Fat Freddie or Fat Freddie’s Cat (this takes several tabs to form a complete picture); Flintstones (character); flying saucer; green dragon (the picture of the dragon is made up from four tabs; aside from green, the dragon may be red, purple or pink, red being the strongest); happy face; Mad comic; Mickey Finn; microdot; millennium [...] penguin; phone; Pink Panther; pirate; planet; policeman; purple Om; pyramid; shield; smiley; Snoopy; Sonic (the Hedgehog); strawberry; Superman; tables and chairs; traffic light and zebra.