surveillance
- 01 C1 Advanced
the act of watching a person or place carefully, often using cameras or technology, to stop crime.
the systematic observation of places or persons by visual, electronic, or other technical means for security or investigative purposes.
Simple“The bank installed new surveillance cameras to watch the entrance 24 hours a day.”
In context“The intelligence agency maintained constant electronic surveillance on the suspect's communications to identify potential accomplices.”
UsageOften used as an uncountable noun or as a modifier in phrases like 'surveillance equipment' or 'surveillance footage'.
Teacher's tipLearners often misspell this word; remind them of the double 'l' and the 'ei' sequence.
Synonyms - 02 C1 Advanced
the process of tracking how a disease spreads to keep people safe.
the continuous, systematic collection and analysis of health data for the planning and evaluation of public health practice.
Simple“Health officials used disease surveillance to find out where the flu was spreading fastest.”
In context“Epidemiological surveillance is critical for detecting early signs of an outbreak before it reaches a pandemic scale.”
UsageCommonly appears in the phrase 'public health surveillance'.
Teacher's tipIn this context, the word is almost always uncountable.
Synonyms
“Flock markets its products as crime-fighting tools for law enforcement and private groups such neighbourhood watch committees, but critics accuse the company of operating a system of mass surveillance with little oversight.”
“The government, German said, also appeared to be relying on theories of “guilt by association” to justify surveillance instead of narrower investigations focused on specific alleged criminal activity.”
Unadapted borrowing from French surveillance (“a watching over, overseeing, supervision”), from surveiller (“to watch, oversee”), from sur- (“over”) + veiller (“to watch”), from Middle French, from Old French veillier (“to stay awake”), from Latin vigilāre (“to be watchful”). More at vigilant.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.