surveillance

ser-VAY-luhnss /sɜːˈveɪləns/
nounB2IELTSTOEFLSAT
generallegalmedical

Close observation, especially of a suspected spy or criminal, or of a disease.

In public health, it refers to the ongoing, systematic collection and analysis of health data to monitor outbreaks.

The story behind the word. Borrowed from French in the early 19th century, literally meaning 'watching over'. It was originally used in the context of the police watching suspects during the French Revolution.

Word relationships

  • monitoring: Monitoring is a broader term; surveillance often implies a more formal or rigorous system of watching.
  • scrutiny: Scrutiny is intense examination, often of documents or behavior, rather than ongoing observation.
  • neglect: The failure to watch or care for something.

Word family

  • survey (verb/noun): To look carefully and thoroughly at (someone or something).

Collocations

  • disease surveillance
  • under surveillance
  • surveillance data

Example sentences

  • "Global surveillance systems are essential for detecting new flu strains before they become pandemics." Disease monitoring.
  • "The building is under 24-hour video surveillance to prevent unauthorized entry." Security context.

Memory hook

Surveillance is like a 'Survey' that never ends. Watch over.

When not to use

Do not use when you mean a one-time 'inspection' or 'check-up'. Surveillance is continuous.

Fun facts

  • Wastewater surveillance—testing sewage for fragments of viruses—has become a key tool for tracking disease levels in cities without testing individual people.

Related words

mitigation, quarantine

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