Definition of surveillance noun from the Oxford Advanced Learner's Dictionary

 

surveillance

 noun
noun
BrE BrE//sɜːˈveɪləns//
 
; NAmE NAmE//sɜːrˈveɪləns//
 
[uncountable] Solving crime, Terrorism
 
jump to other results
the act of carefully watching a person suspected of a crime or a place where a crime may be committed synonym observation The police are keeping the suspects under constant surveillance. surveillance cameras/equipment See related entries: Solving crime, Terrorism Word Origin early 19th cent.: from French, from sur- ‘over’ + veiller ‘watch’ (from Latin vigilare ‘keep watch’).Extra examples The country’s borders are kept under constant surveillance. The images were covertly captured on surveillance tape. The suspects are under police surveillance. The police are keeping the suspects under constant surveillance. There are surveillance cameras mounted above each entrance.
See the Oxford Advanced American Dictionary entry: surveillance