surveillance

Etymology

Borrowed from French surveillance (“a watching over, overseeing, supervision”), from surveiller (“to watch, oversee”), from sur- (“over”) + veiller (“to watch”), from Middle French, from Old French veillier (“to stay awake”), from Latin vigilāre, present active infinitive of vigilō (“I am watchful”). More at vigilant.

noun

1. Close observation of an individual or group; person or persons under suspicion.
2. Continuous monitoring of disease occurrence for example.
3. (military, espionage) Systematic observation of places and people by visual, aural, electronic, photographic or other means.
   The threat of terrorism to the British lies in the overreaction to it of British governments. Each one in turn clicks up the ratchet of surveillance, intrusion and security. Each one diminishes liberty. 2012-12-14, Simon Jenkins, “We mustn't overreact to North Korea boys' toys”, in The Guardian Weekly, volume 188, number 2, page 23
   Cook was making an impassioned plea to end the technology industry’s collection and sale of user data. “This is surveillance,” he continued. 2019-01-31, Ian Bogost, quoting Tim Cook, “Apple’s Empty Grandstanding About Privacy”, in The Atlantic
4. (law) In criminal law, an investigation process by which police gather evidence about crimes, or suspected crime, through continued observation of persons or places.