operation

/op'euh ray"sheuhn/, n.

1. an act or instance, process, or manner of functioning or operating.

2. the state of being operative (usually prec. by in or into): a rule no longer in operation.

3. the power to act; efficacy, influence, or force.

4. the exertion of force, power, or influence; agency: the operation of alcohol on the mind.

5. a process of a practical or mechanical nature in some form of work or production: a delicate operation in watchmaking.

6. a course or procedure of productive or industrial activity: building operations.

7. a particular process or course: mental operations.

8. a business transaction, esp. one of a speculative nature; deal: a shady operation.

9. a business, esp. one run on a large scale: a multinational operation.

10. Surg. a procedure aimed at restoring or improving the health of a patient, as by correcting a malformation, removing diseased parts, implanting new parts, etc.

11. Math.

a. a mathematical process, as addition, multiplication, or differentiation.

b. the action of applying a mathematical process to a quantity or quantities.

12. Mil.

a. a campaign, mission, maneuver, or action.

b. Usually, operations. the conduct of a campaign, mission, etc.

c. operations, a headquarters, office, or place from which a military campaign, air traffic to and from an airfield, or any of various other activities, is planned, conducted, and controlled.

d. operations, the people who work at such a headquarters.

[1350-1400; ME operacioun < L operation- (s. of operatio), equiv. to operat(us) (see OPERATE) + -ion- -ION]

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