Operation

[op-uh-rey-shuh n] /ˌɒp əˈreɪ ʃən/

noun
1.
an act or instance, process, or manner of functioning or operating.
2.
the state of being operative (usually preceded 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, especially one of a speculative nature; deal:
a shady operation.
9.
a business, especially one run on a large scale:
a multinational operation.
10.
Surgery. 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.
Mathematics.

12.
Military.

/ˌɒpəˈreɪʃən/
noun
1.
the act, process, or manner of operating
2.
the state of being in effect, in action, or operative (esp in the phrases in or into operation)
3.
a process, method, or series of acts, esp of a practical or mechanical nature
4.
(surgery) any manipulation of the body or one of its organs or parts to repair damage, arrest the progress of a disease, remove foreign matter, etc
5.

6.
(maths)

7.
a commercial or financial transaction
n.

late 14c., “action, performance, work,” also “the performance of some science or art,” from Old French operacion “operation, working, proceedings,” from Latin operationem (nominative operatio) “a working, operation,” from past participle stem of operari “to work, labor” (in Late Latin “to have effect, be active, cause”), from opera “work, effort,” related to opus (genitive operis) “a work” (see opus). The surgical sense is first attested 1590s. Military sense of “series of movements and acts” is from 1749.

operation op·er·a·tion (ŏp’ə-rā’shən)
n.

operation
(ŏp’ə-rā’shən)