Green’s Dictionary of Slang

pig adj.

[pig n. (2)]

1. pertaining to the police.

[UK]J. Mandelkau Buttons 143: I contemplated ripping off a pig landrover.
[US](con. 1967) Bunch & Cole Reckoning for Kings (1989) 45: Ain’t no way to bribe them pig MPs at the wire.
[US]Crow Dog & Erdoes Lakota Woman 120: All these Indians and they can’t total one lousy pig car!
[UK]I. Welsh ‘Stoke Newington Blues’ in Acid House 41: Ah’m gaunny git sorted wi this pig gear.
[Ire]P. Howard The Joy (2015) [ebook] We went down to the pig station and [...] into this interview room.
[UK]N. Griffiths Grits 97: Fuckin pig spy, that cunt is like.

2. (US) pertaining to the white Establishment.

[US](con. 1970) J.M. Del Vecchio 13th Valley (1983) 364: This pig shit. This white man’s war.