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

The South's joint chiefs said Saturday the military stepped up surveillance and vigilance for possible further launches from the North and was closely sharing information with the United States and Japan. — Arkansas Online, 4 Oct. 2026

Chinese media also reported that participating forces were stationed underground during the exercise to protect them from drone attacks, illustrating how persistent aerial surveillance and strike drones are changing battlefield operations. — Bojan Stojkovski, Interesting Engineering, 4 Oct. 2026

Jurors repeatedly reviewed surveillance video capturing the hours, minutes and seconds leading to the shooting before ultimately deadlocking on the homicide charges. — Daniel Hunt, Sacbee.com, 3 Oct. 2026

The judge said the case demonstrated why courts may need to reconsider how older Fourth Amendment precedents apply as surveillance technology advances. — Rena Rowe, The Washington Examiner, 3 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