spook
n.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.
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”).