- 1 [countable] the process of cutting open a part of a person's body in order to remove or repair a damaged part Will I need to have an operation? He underwent a three-hour heart operation. operation (on somebody/something) (to do something) an operation on her lung to remove a tumor operation (on somebody/something) (for something) Doctors performed an emergency operation for appendicitis last night. organized activity
- 2 [countable] an organized activity that involves several people doing different things a security operation The police have launched a major operation against drug dealers. the UN peacekeeping operations business
- 3[countable] a business or company involving many parts a huge multinational operation
- 4[countable] the activity or work done in an area of business or industry the firm's banking operations overseas computer
- 5[countable, uncountable] an act performed by a machine, especially a computer The whole operation is performed in less than three seconds. machine/system
- 6[uncountable] the way that parts of a machine or a system work; the process of making something work Regular servicing guarantees the smooth operation of the engine. Operation of the device is extremely simple. military activity
- 7[countable, usually plural] military activity He was the officer in charge of operations. mathematics
- 8[countable] a process in which a number or quantity is changed by adding, multiplying, etc. Idioms
nounjump to other results
to start working; to start having an effect synonym come into force The new rules will come into operation next week.
come into operationjump to other results
working, being used, or having an effect The system has been in operation for six months. Temporary traffic controls are in operation on Route 47.
in operationjump to other results
to make something start working; to start using something It's time to put our plan into operation.
put something into operationjump to other results