Meaning of OPERATION in English

OPERATION

/ ˌɒpəˈreɪʃn; NAmE ˌɑːp-/ noun

MEDICAL

1.

(also BrE informal op ) [ C ] operation (on sb) (for sth) | operation (to do sth) the process of cutting open a part of a person's body in order to remove or repair a damaged part :

an operation on her lung to remove a tumour

Will I need to have an operation ?

He underwent a three-hour heart operation.

Doctors performed an emergency operation for appendicitis last night.

ORGANIZED ACTIVITY

2.

[ C ] an organized activity that involves several people doing different things :

a security operation

The police have launched a major operation against drug suppliers.

the UN peacekeeping operations

BUSINESS

3.

[ C ] a business or company involving many parts :

a huge multinational operation

4.

[ C ] the activity or work done in an area of business or industry :

the firm's banking operations overseas

COMPUTER

5.

[ C , U ] an act performed by a machine, especially a computer :

The whole operation is performed in less than three seconds.

MACHINE / SYSTEM

6.

[ U ] the way that parts of a machine or a system work; the process of making sth work :

Regular servicing guarantees the smooth operation of the engine.

Operation of the device is extremely simple.

MILITARY ACTIVITY

7.

[ C , usually pl. ] military activity :

He was the officer in charge of operations.

MATHEMATICS

8.

[ C ] a process in which a number or quantity is changed by adding, multiplying, etc.

IDIOMS

- in operation

- come into operation

- put sth into operation

••

WORD ORIGIN

late Middle English : via Old French from Latin operatio(n-) , from the verb operari expend labour on, from opus , oper- work.

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.