Pig

noun

pig

Police officer. "pig" as a synonym for policeman" has been around for about two hundred years (according to "Partridge's Concise Dictionary of Slang and Unconventional English"). It did, however, disappear in the late nineteenth century (or, as the dictionary says "go underground" though I'm not sure what they mean by that) and reappear in common usage around 1960. I know that during Prohibition speakeasies who had bribed the local police to not bother them were called "blind pigs" (The Blind Pig bar here in Ann Arbor actually used to be such a place). I suspect that the term has been used to mean any kind of unpleasant person since humans started domesticating the things...

This pig harassed the whole neighborhood,

Well this pig worked at the station.

This pig he killed my Homeboy,

So the fuckin' pig went on a vacation.

This pig he is the chief,

Got a brother pig, Captain O'Malley.

He's got a son that'a a pig too,

He's collectin' pay-offs from a dark alley.

-- Cypress Hill (Pigs) [1]