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operation

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noun American English pronunciation: operation /ˌɑpəˈreɪʃ(ə)n/ 
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singularoperation
pluraloperations
 
  1. 1
    [countable] a planned activity involving a lot of people, especially soldiers or police officers

    This was the biggest military operation in 20 years.

    Undercover operations led to the arrest of the gang.

    rescue/relief/cleanup operation:

    The cleanup operation will take weeks.

    Thesaurus entry for this meaning of operation
  2. 2
    [countable] an action or set of actions that is necessary to achieve something

    Connecting the water supply is a very simple operation.

    The computer performs this operation many times every day.

    Thesaurus entry for this meaning of operation
  3. 3
    [countable] the process of cutting into someone's body for medical reasons

    a stomach/heart operation

    have/undergo an operation:

    The baby had to have an operation, but he's fine now.

    operation on:

    She may need an operation on her knee.

    do/perform/carry out an operation:

    A very experienced heart surgeon will perform the operation.

    Thesaurus entry for this meaning of operation
  4. 4
    [uncountable] the way that something such as a system or service operates

    We are visiting schools to explain the operation of the new exam system.

    Thesaurus entry for this meaning of operation
    1. a.
      used about the way that a machine or piece of equipment operates

      Something was interfering with the radar equipment's operation.

      Thesaurus entry for this meaning of operation
    2. b.
      used about the way that something such as a rule or an idea is used

      Science investigates the operation of general laws.

      Thesaurus entry for this meaning of operation
  5. 5
    [countable] a company, or a part of a large company

    The company has recently expanded its international operation.

    The group is selling its overseas operations.

    Thesaurus entry for this meaning of operation
  6. 6
    [uncountable] the process of controlling something or of making it work

    Operation of this equipment requires special training.

    Thesaurus entry for this meaning of operation

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This is the American English definition of operation. View British English definition of operation.

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