Green’s Dictionary of Slang

1. an operation, i.e. an activity.

1921		N&Q 12 Ser. IX 416: Our recollections of training abound with harrowing experiences of ‘night opps’ (operations).
1930		H. Ashton Doctor Serocold (1936) 157: Beastly difficult op.; I hate it.
1941		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 3 May 9/5: ’Tis said she conquered the op. for appendix and once again has her kix.
1946		G. Gibson Enemy Coast Ahead (1955) 169: I sat up late in the Ops room waiting for them to return.
1958		J. Osborne Epitaph for George Dillon Act II: It was one night in particular, when it wasn’t my turn to go on ops.
1978		J. Webb Fields of Fire (1980) 149: ‘What do you need?’ ‘Somebody from that op.’.
1986		C. Stroud Close Pursuit (1988) 212: Are we blue-skying it here? Are we into a covert op situation-wise?
1990		(con. c.1970) G. Hasford Phantom Blooper 28: We will not pull patrols. We will not set ambushes. We will not go out on ops.
2001		A. Sillitoe Birthday 168: His two tours of ops.
2009		(con. 1960s) J. Ellroy Blood’s a Rover 16: Wayne Senior was jungled up all over the nut Right. He did Klan ops for Mr Hoover.
2013		K. Sampson Killing Pool 107: Lanky knew this op was coming off!
2018		C. Hammer Scrublands [ebook] ‘Did you find any evidence in the flat that Haus-Jones was involved with the drug op?’.
2023		M. Herron Secret Hours 317: ‘I won’t just have been dipping my hand in the Service pot. I’ll have been running an off-the-book op on foreign soil’.
2023		(con. 1962) J. Ellroy Enchanters 239: ‘My Hoffa op. How far is it blow?’.

2. (US) a private investigator [abbr. SE operative; thus Dashiell Hammett’s (1894–1961) fictional detective the ‘Continental Op’].

1926		‘Und. and Its Vernacular’ in Clues mag. 158—62: op Private detective agency operator.
1927		D. Hammett ‘$106,000 Blood Money’ Story Omnibus (1966) 333: That runt who came after me was one of your ops – tailing me.
1933		‘Paul Cain’ ‘One, Two, Three’ in Penzler Pulp Fiction (2006) 3: I ran into an op for Eastern Investigators, Inc.
1947		S.J. Perelman ‘Farewell, My Lovely Appetiser’ in Keep It Crisp 12: I haven’t been a private op nine years for nothing.
1958		R. Chandler Playback 138: You’re a private op.
2005		E. Weiner Big Boat to Bye-Bye 255: ‘Yeah, I’m a bent op, and you’re a gumshoe with a halo’.

3. a surgical operation.

1929		W. Winchell On Broadway 17 Dec. [synd. col.] Jack Fugazy, the fight promter, will undergo a major op at the Park East hosp this week.
1937		C.R. Prance Tante Rebella and her Friends (1951) 45: The doctor, who did Oom Betje’s ‘op’ at a special discount for cash in advance.
1952		W. Winchell ‘On Broadway’ 11 Sept. [synd. col.] Nancy Thompson [...] is on the mend following a major op.
1959		J. Gosling Ghost Squad 49: Hope the wife’s going to be all right, you never can tell after an op. like that, can yer?
1971		J. McClure Steam Pig 19: I’ve seen blood hit the ceiling with an aneurism that burst during an op.
1985		S. Berkoff West in Decadence and Other Plays (1985) 103: After the op he turned all funny for a while.
1992		D. Jarman diary 8 Nov. Smiling in Slow Motion (2000) 252: He had a lung op.
2005		H. Mantel Beyond Black 173: I never say a big op. It doesn’t do to upset people.
2012		P. Corris ‘Prodigal Son’ in Crime Factory: Hard Labour [ebook] They’re trying to build me up to take the op in a week. I’d like to see Ivan before I go under.

4. (US) an operator of any kind, e.g. a telephone or telegraph operator.

1922		M.E. Smith Adventures of a Boomer Op. 14: You could stand by the sailors monument, there at the entrance and throw a stone at random and hit an op’ at every throw.
1931		Irwin Amer. Tramp and Und. Sl. 138: Op.–A telegraph operator.
1934		R.L. Bellem ‘Sleeping Dogs’ in Spicy Detective Sept. 🌐 I went past the telephone op. He was reading a magazine and didn’t see me.
1938		L. Beebe High Iron 222: Op: Telegrapher.
1946		G. Gibson Enemy Coast Ahead (1955) 179: Until the wireless-op. (Hutch) says ‘Intercom. O.K.’.
1951		W. Winchell ‘On Broadway’ 13 May [synd. col.] Isn’t the new night switchboard op at the Hotel Stanhope Vincent (zillions) Stanhope.
1969		J. Crumley One to Count Cadence (1987) 48: I thought perhaps he might not be a good Morse op.
1999		K. Sampson Powder 59: Ben, the spotty young tape-op was carried around the studio shoulder-high.