Sleeper
Spook
Spook noun - A person who tries secretly to obtain information for one country in the territory of another usually unfriendly country.
Usage example: Russia recalled its spooks after the collapse of the Soviet Union
Mutual synonyms
Cite this Source
Spook and Sleeper. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/sleeper/spook
Sleeper & Spook. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/sleeper/spook>.
Spook or Sleeper. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/sleeper/spook.
Google Ngram Viewer shows how "sleeper" and "spook" have occurred on timeline