Definition of operation in English:


Line breaks: op¦er|ation
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.
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
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.
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.
More 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.


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

Definition of operation in: