Definition of "spook"

"I'll say what I think, no more and no less, and I won't be scared by you or your spooks into altering my opinions."

1925 July – 1926 May, A[rthur] Conan Doyle, “(please specify the chapter number)”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019

From Ian Fleming to John Le Carre - authors have long been fascinated by the world of espionage. But, asks the BBC’s Gordon Corera, what do real life spooks make of fictional spies?

2009 July 24, “Spies like them”, in BBC News Magazine

The congressional study frets that Huawei’s and ZTE’s products could be used as Trojan horses by Chinese spooks.

2012 October 13, “Huawei and ZTE: Put on hold”, in The Economist‎

Some won't take spooks—hell, don't make no difference to me.

1976, Paul Schrader, Taxi Driver, spoken by Travis Bickle (Robert De Niro)

" […] Dryades Street and that whole uptown neighborhood is gonna be worth a fortune once the white people take it back from you spooks and develop it. […] "

2002 February, Don Spears, Playing for Keeps‎, Los Angeles: Milligan Books, page 179

He who is infatuated with Man leaves persons out of account so far as that infatuation extends, and floats in an ideal, sacred interest. Man, you see, is not a person, but an ideal, a spook.

1845, Max Stirner, translated by Steven T. Byington, Der Einzige und sein Eigentum; republished as The Ego and His Own, Dover, 2005

Commonly, the surgeons view nonsurgeons with disdain. The most disdain is directed toward the “shrinks” or the “spooks,” as the psychiatrists are called.

1975, Robert O. Pasnau, Consultation-Liaison Psychiatry, page 124

As that was happening, an East Midlands train came through at 90mph. George [a Labrador] was spooked as the train went past him and ran backwards across the neighbouring slow lines and off towards the sidings.

2022 August 10, “Stop & Examine”, in RAIL, number 963, page 71