operation

noun

US /ˌɑpəˈreɪʃ(ə)n/

Word Forms

singular	operation
plural	operations

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.
Synonyms and related words
A military or armed attack
air raid
air strike
attack
Synonyms and related words
Crime detection and prevention
agent provocateur
all-points bulletin
Amber alert
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.
Synonyms and related words
General words for actions and activities
action
thing
operation
Synonyms and related words
A series of actions or activities
series
process
campaign
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.
Synonyms and related words
Medical operations
abortion
angioplasty
appendectomy
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.
Synonyms and related words
Systems and methods for doing things
modality
method
system
1. 4a
  used about the way that a machine or piece of equipment operates
  Something was interfering with the radar equipment’s operation.
  Synonyms and related words
  To work, or to start working (of a piece of machinery)
  operate
  come on
  function
2. 4b
  used about the way that something such as a rule or an idea is used
  Science investigates the operation of general laws.
  Synonyms and related words
  Use of something
  application
  consumption
  exploitation
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.
Synonyms and related words
General types of business or company
account
acquisition
affiliate
6
uncountable the process of controlling something or of making it work
Operation of this equipment requires special training.
Synonyms and related words
Use of something
application
consumption
exploitation

phrases

in operation

into operation

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operation ​‌‌‌

operation

operation