surveillance

noun

sur·​veil·​lance sər-ˈvā-lən(t)s 

also

-ˈvāl-yən(t)s 

or

-ˈvā-ən(t)s 

: close watch kept over someone or something (as by a detective)

also : supervision see also immune surveillance

Synonyms of surveillance

• stewardship
• supervision
• oversight
• management
• control
• policing
• regulation

Examples of surveillance in a Sentence

government surveillance of suspected terrorists

The bank robbery was recorded by surveillance video cameras.

Recent Examples on the Web

Several aircraft could divide surveillance tasks or combine their efforts to improve coverage in a particular sector. — Bojan Stojkovski, Interesting Engineering, 24 Oct. 2026

Authorities are using drone surveillance, checks at railway stations, rapid-response units and online monitoring for potential calls to violence. — ABC News, 24 Oct. 2026

Investigators say that surveillance video of the kidnapping shows a man wearing black gloves getting out of the same vehicle. — Milena Malaver, Miami Herald, 23 Oct. 2026

In the wake of 9/11, the New York Police Department built one of the most sophisticated and omnipresent surveillance systems in the country. — Amanda Aronczyk, NPR, 23 Oct. 2026

Word History

Etymology

French, from surveiller to watch over, from sur- + veiller to watch, from Old French veillier, from Latin vigilare, from vigil watchful — more at vigil

First Known Use

1802, in the meaning defined above

Phrases Containing surveillance

• counter-surveillance
• electronic surveillance
• immune surveillance
• immunological surveillance
• keep under surveillance

Kids Definition

surveillance

noun

sur·​veil·​lance sər-ˈvā-lən(t)s 

also -ˈvāl-yən(t)s

or -ˈvā-ən(t)s

: close watch

under surveillance

Medical Definition

surveillance

noun

sur·​veil·​lance

sər-ˈvā-lən(t)s also -ˈvāl-yən(t)s or -ˈvā-ən(t)s

: close and continuous observation or testing

serological surveillance

see immune surveillance