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

• 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

Donell Harvin, a homeland security and public health emergency expert at Georgetown University, told CNN on Sunday that the attacker may have conducted pre-operational surveillance and come up with a plan that maximizes fatalities and damage. —Jason Ma, Fortune, 29 Sep. 2025

The suspect also appeared on surveillance video disguised in sunglasses and a baseball cap, Rogers noted. —Michael Ruiz, FOXNews.com, 28 Sep. 2025

The surveillance video shows several detainees, whose arms and legs were shackled, being hurried into the building with the help of federal agents. —Harriet Ramos, Fort Worth Star-Telegram, 27 Sep. 2025

The investigations are based on cellphone records, surveillance footage and other details, like a release of liability form in Thomas’ girlfriend’s name, which was associated with a car seen fleeing burglaries in Orinda, Novato and Oakley, authorities said. —Nate Gartrell, Mercury News, 26 Sep. 2025

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