surveillance
- 1Close observation of an individual or group, especially someone under suspicion.
The detective placed the apartment under round-the-clock surveillance.
Constant surveillance of the suspect eventually revealed his contacts.
Similarobservation, watch, monitoring, scrutiny
Note
A French word taken over whole, spelling and all: sur- "over" plus veiller "to watch", which runs back through Old French veillier "to stay awake" to Latin vigilāre, the root of vigilant. The picture underneath is a sleepless watch kept over someone. It is usually a mass noun, as in kept under surveillance, but it can also count single operations: two surveillances running at once.
- 2The use of sight, listening, cameras, electronic equipment, or other means to observe people and places systematically.
Government agents maintained surveillance on the embassy for months.
Electronic surveillance intercepted the group's encrypted messages.
Similarmonitoring, observation, spying
Note
The sense that has become a political argument. Simon Jenkins, writing in 2012, set it beside intrusion and security as one more turn of a ratchet that diminishes liberty. In 2019 Tim Cook said "This is surveillance" of the tech industry's collection and sale of user data, carrying the word from spies to companies. Its compounds name the hardware: surveillance cameras, surveillance capabilities.
- 3Sustained observation of people or places as a way for police to collect evidence about actual or suspected crimes.
Detectives kept the suspect under surveillance to document his meetings with the dealer.
The court ruled that the surveillance had been conducted without a proper warrant.
Similarobservation, watch
Note
In criminal procedure, watching is a way of building a case, so it has to be justified. When observation intrudes on a reasonable expectation of privacy, judicial authorization is often required, and a warrant becomes the point a court may later test. The end product is evidence for trial. That separates it from intelligence and state watching, whose product is information rather than proof.
- 4Continuous monitoring of how often a disease occurs within a population.
Public health surveillance detected a sudden rise in measles cases.
Continuous surveillance of mosquito populations warned officials of a coming malaria season.
Similarmonitoring
Note
The public-health use, where nobody is under suspicion. What is watched is a pattern counted over time, such as cases, outbreaks or mosquito numbers, rather than a person. Its typical partners follow from that: disease surveillance, public health surveillance. The aim is early detection, not proof. That purpose is what sets it apart from the watching of a suspect, where the individual is the target.
Practice
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Origin
A borrowing from French surveillance ('a watching over, supervision'), from surveiller ('to watch, oversee'), formed from sur- ('over') plus veiller ('to watch'). This traces back through Old French veillier ('to stay awake') to Latin vigilāre ('to be watchful').