Definition of operation in English:

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Pronunciation: /ɒpəˈreɪʃ(ə)n/


1 [mass noun] The action of functioning or the fact of being active or in effect: restrictions on the operation of market forces the company’s first hotel is now in operation
More example sentences
  • The company has eight power plants in operation and seven under construction.
  • Maybe I don't but there needs to be work done even if just to prove that the Placebo effect is in operation.
  • Since 1997, some 40 hospitals and 550 schools are under construction or in operation.
functioning, working, running, performance, action, behaviour
effect, force, potency, power, effectiveness
functioning, working, running, up and running, operative, in use, in action, going;
operational, workable, serviceable, functional, usable, in working order/condition, viable;
in force, effective, in effect, valid
1.1 [count noun] An active process; a discharge of a function: the operations of the mind
More example sentences
  • The attorney general really has no direct relation to the operation and function of the election operations in each of these counties.
  • As we said last November, they're not mentioned in the Reserve Bank Act 1959 or its own overview of its functions and operations.
  • Because these operations discharge uneaten food, pesticides and fish waste into the ocean, they need permits.
2An act of surgery performed on a patient: I’ve never felt better since my bypass operation
More example sentences
  • To avoid this problem, some surgeons perform coronary bypass operations on beating hearts.
  • Vasectomy can easily be performed as an outpatient operation under local anaesthetic.
  • Patients can visit day surgery units for small operations and be allowed to return home later in the day or evening.
surgery, surgical operation, surgical intervention, major surgery, minor surgery
3 [often with adjective or noun modifier] An organized activity involving a number of people: a rescue operation [in names]: Operation Desert Storm
More example sentences
  • His leadership combined military operations, government administration, and economic management.
  • Arguably they are too late, since the unprecedented military operation staged to rescue her was itself a made for-TV movie directed by the Pentagon.
  • The official avoided making specific comments on the possibility of a U.S.-led military operation to rescue Koda.
action, activity, exercise, affair, business, undertaking, step, enterprise, task, job, process, procedure, manoeuvre, campaign
3.1A business organization; a company: he reopened his operation under a different name
More example sentences
  • Today, the companies are vastly different operations and producing returns at opposite ends of the scale for their owners.
  • Inquiries about a private operation produced an estimate of £19,000.
  • Most companies have not made the transition from being multi-region organizations to truly global operations.
business, enterprise, company, firm, organization, concern
informal outfit, set-up
3.2An activity in which a business is involved: the company is selling most of its commercial banking operations
More example sentences
  • The sequence of banking operations involved in payment turns, in part, on whether there is a credit transfer or debit transfer.
  • I'm not really involved in the day-to-day operations of the business, but I'm trying to get more and more involved.
  • They are long on management talent and typically expect to be involved in the day-to-day operations of acquired businesses.
4 Mathematics A process in which a number, quantity, expression, etc., is altered or manipulated according to set formal rules, such as those of addition, multiplication, and differentiation.
Example sentences
  • Problems can be created to cover all math operations of addition, subtraction, multiplication and division!
  • That is addition, multiplication and the two inverse operations of subtraction and division.
  • For example, one can have a group in which the objects are numbers and the combining operation is addition or multiplication.



come into (or go out of) operation

Begin (or cease) functioning or having effect: our new system has come into operation
More example sentences
  • He may have entered Ireland before the database came into operation in 2001.
  • Please note that most of the VAT amendments have come into operation on 1 October.
  • In the meantime a rota system came into operation whereby the children took turns to weed, water, and generally care for the seedling vegetables.

put something into operation

Cause something to begin functioning or having effect: the government is going to put this plan into operation
More example sentences
  • The group is putting the cameras into operation because the road has a bad record of crashes.
  • The announcement had not come as a complete surprise and airlines involved had put contingency plans into operation.
  • The first round of the new project will be put into operation in March.


Late Middle English: via Old French from Latin operatio(n-), from the verb operari 'expend labour on' (see operate).

  • office from Middle English:

    In the Middle Ages office meant a duty that went with someone's position or employment. It goes back ultimately to Latin officium ‘performance of a task’, which in turn comes from the combined elements of opus ‘work’ (source of English opus in the early 19th century and of operation (Late Middle English)) and facere ‘to do’. The sense of ‘a place for business’ is recorded from the later Middle Ages. Someone officious (Late Middle English) was originally obliging or efficient in carrying out their office. The word developed its modern negative sense at the end of the 16th century.

For editors and proofreaders

Line breaks: op¦er|ation

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