op‧e‧ra‧tion S1 W1


[countable]MH the process of cutting into someone's body to repair or remove a part that is damagedCOLLOCATIONS COLLOCATIONS
have an operation undergo an operation formal (=have an operation) perform an operation major/minor operation emergency operation routine operation (=an operation that is often performed) life-saving operation
a heart bypass operation
operation on/for
She's going to need an operation on her ankle.
He had an operation to reduce the swelling in his brain.
She underwent a minor operation on her elbow in the summer.
the surgeon who performed the operation
The poor man had two major operations in two weeks.
an emergency operation to save his sight
a routine knee operation
The first indications were that the life-saving operation had gone well.
! Do not say that someone 'takes an operation'. Say that they have an operation.


[countable]BB a business, company, or organization:
The firm set up its own property development operation.
a microchip manufacturing operation
Nolan and Barnes were both involved in the operation.


[uncountable and countable]BB the work or activities done by a business or organization, or the process of doing this work:
Many small businesses fail in the first year of operation.
The Education Business Partnership has been in operation since 1989.


[countable] a set of planned actions or activities for a particular purpose:
The UN rescue operation started shortly after dawn.


[uncountable]T the way the parts of a machine or system work together, or the process of making a machine or system work:
The aircraft's engine operation was normal.
in operation
Protective clothing must be worn when the machine is in operation.
The device has a single button, allowing for easy operation.
Careful checks must be made before the factory commences operation.
The new investment system came into operation in 1999.

principle/law/plan etc

[uncountable] the way something such as a principle or law works or has an effect
in operation
a clear example of the law of gravity in operation
come/go into operation (=begin to have an effect)
The new rule comes into operation on February 1.
put/bring something into operation (=make something start to work)
A scheme is being brought into operation to see how these changes would work.

military/police action

[countable]PMSCP a planned military or police action, especially one that involves a lot of people:
Britain will carry out a joint military operation with the US.


[countable]TD an action done by a computer

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