Green’s Dictionary of Slang

1. a uniformed police officer.

1928		C. McKay Home to Harlem 197: ‘What’s matter? Scared of a uniform? Pat’ — she turned to the policeman — ‘what you want to throw a scare in the company for?’.
1974		G.F. Newman You Flash Bastard 71: Detectives followed him, and the two uniforms, one with his labrador for sniffing out dope.
1986		R. Campbell In La-La Land We Trust (1999) 27: Two uniforms got out of the squad car, setting their caps and bolstering their batons.
1997		Simon & Burns Corner (1998) 4: Curt is still on post [...] when the Western uniforms roll up for a last pass at the corner.
2001		G. Pelecanos Right As Rain 184: Ray caught a quick glimpse of the uniform behind the wheel, a big ugly spade who was staring straight ahead.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 196/2: uniform n. guard, or metonymy.
2002		Simon & Burns ‘The Target’ Wire ep. 1 [TV script] You got the uniforms on the horn?
2004		L. Redhead Peepshow [ebook] ‘We’re here about the Parisi murder,’ I told a young cop [...] The uniform grinned.
2011		G. Knight Hood Rat 179: He is surrounded by four uniform, who are turfing out his pockets.
2012		C. Stella Rough Riders 8: He took a swing at one of the uniforms and got tagged by the one with the gun.
2017		D. Winslow The Force [ebook] The ‘uniforms’ in their bags don’t look like your run-of-the-mill cops either.

2. (gay) a member/members of the armed or uniformed services.

1941		G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.
1965		H. Rhodes Chosen Few (1966) 252: Another party of uniforms arrived.
1970		San Diego Sailor 3: [...] the assumption that a uniform was a pushover for anyone who played it right. [Ibid.] 29: The civvies were sure busy going for the uniforms.
2000		Guardian Guide 22–28 Jan. 9: Then he took some coke and headbutted some ‘uniforms.’.

3. a prison officer.

1977

G.F. Newman A Prisoner’s Tale 107: ‘I fetched it in with me,’ Lynn said, handing the uniform the book.