Green’s Dictionary of Slang

cop n.1

[note Cumbrian dial. cop, a prison]

1. [mid-19C+] (orig. US) a police officer.

2. [late 19C+] (orig. US) an arrest; esp. in the old (and prob. fictional) cliché, It’s a fair cop, guv, slap the bracelets on.

3. [1920s] (UK prison) an inmate.

4. [1930s] a sentence.

5. [1970s+] (US prison) a warder, a guard.

In derivatives

copess (n.)

see separate entry.

In compounds

copbusy (v.)

see separate entry.

cop house (n.)

[1920s+] (US) a police station.

cop killer (n.)

[1980s+] (US) a Teflon-coated bullet capable of penetrating the body armour worn by police officers; such bullets are outlawed.

copman (n.)

see separate entry.

cop shop (n.) [shop n.1 (1)]

[1910s+] (orig. Aus.) a police station; cite 2008 refers to a city’s police department.

In phrases

horse cop (n.)

[1940s+] (US) a police officer riding a horse.

soft cop (n.) [note the trad. hard cop/soft cop interrogation routine]

[1980s+] a gullible, well-meaning person, e.g. a community/social worker whose sympathies can be exploited.

In exclamations

cop bung! [fig. use of bung v.1 (4)]

[late 19C] (UK Und.) look out! the police are coming!