Pronunciation: (op"u-rā'shun),[key] —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.