spook
n.a person who works for a secret government agency, like the police or the military. It is a short, informal way to say 'spy'.
n.a person who works for a secret government agency, particularly in the context of intelligence or law enforcement. Informal and often considered vulgar in certain professional circles.
“He used to be a spook for the government.”
“The retired spook shared some interesting stories about his time working undercover in foreign countries.”
“While the former spook was reluctant to speak publicly, he eventually agreed to testify before the committee regarding the security breach.”
“A Texas sheriff’s deputy got the spook of his life and a good laugh during a recent late-night encounter with a deer he mistook for dead on the side of the road.”
“Perhaps the first episode is pandering to the old Clarkson diehards so as not to spook them, before it sets about tearing up the blueprint and making something more distinct.”
Borrowed from Dutch spook (“ghost”), from Middle Dutch spooc (“spook, ghost”). Cognate with Middle Low German spôk, spûk (“apparition, ghost”), Middle High German gespük (“a haunting”), German Spuk, Danish spøge (“to haunt”), Swedish spöke (“ghost”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.