operation

American  

[op-uh-ray-shuhn] / ˌɒp əˈreɪ ʃən /

noun

• operations
  plural

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

2. the state of being operative (usually preceded by in orinto ).

   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.

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

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

12. Computers. any discrete activity or action that is performed by a computer, as reading, writing, processing, sending, or receiving data.

    The http request operation has timed out.

13. Military.

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

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

    3. 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.

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

---

operation British  

/ 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. 1. a military or naval action, such as a campaign, manoeuvre, etc

   2. ( capital and prenominal when part of a name )

      Operation Crossbow

6. maths

   1. any procedure, such as addition, multiplication, involution, or differentiation, in which one or more numbers or quantities are operated upon according to specific rules

   2. a function from a set onto itself

7. a commercial or financial transaction

---

operation Scientific  

/ ŏp′ə-rā′shən /

1. Medicine A surgical procedure for remedying an injury, ailment, defect, or dysfunction.

2. Mathematics A process or action, such as addition, substitution, transposition, or differentiation, performed in a specified sequence and in accordance with specific rules.

3. A logical operation.

4. Computer Science An action resulting from a single instruction.

---

Other Word Forms

Derived Forms

• misoperation
  noun
• preoperation
  noun
• reoperation
  noun
• suboperation
  noun

Inflected Forms

Nouns

• operations
  plural

Etymology

Origin of operation

First recorded in 1350–1400; Middle English operacioun, oparacion, operation, from Latin operātiōn- (stem of operātiō ), equivalent to operāt(us) + -iōn- noun suffix of action or condition; see origin at operate

Explanation

Operation can refer to medical surgery, a military campaign, or mathematical methods, such as multiplication and division. Operation comes from the Latin word opus (“work”) and can refer to a whole range of practical activities and work. In driver's education, you learn the proper operation of a motor vehicle. If you’re going to make your lemonade franchise a success, you’re going to have to learn the rules for prudent operation of a business — how to run it — and you’ll also have to figure out the operation of a lemon squeezer.

Example Sentences

See Examples For:

operation operations

Chief Constable Jon Boutcher has said the policing operation over the Drumcree parading dispute has cost about £3m so far.

From BBC ● Oct. 1, 2026

Seoul says the operation was meant to remain confidential, but Ukrainian President Volodymyr Zelensky revealed the transfer during an address to the United Nations last week -- prompting South Korea to demand an apology.

From Barron's ● Sep. 30, 2026

The inaction follows a record $98.7 billion operation the prior month involving coordination with Washington to defend the Japanese currency after it weakened to 40-year lows near 164 to the dollar in late July.

From The Wall Street Journal ● Sep. 30, 2026

The Department of Homeland Security called the undertaking the “largest DHS operation ever” earlier this year on X, with an estimated 2,000 agents deployed to the Minneapolis–St. Paul metropolitan area.

From Los Angeles Times ● Sep. 30, 2026

“I didn’t. That was her plan. She knew that our Warsaw operation was being dismantled and insisted on supervising. I consented. She was always angling for assignments, and I figured this might scratch that itch.”

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

Ellison isn’t expected to name a news chief to oversee both operations when he lays out his organizational structure for the combined company in the coming days, people familiar with the matter said.

From The Wall Street Journal ● Oct. 1, 2026

Hundreds of jobs are under threat in Grangemouth after an agricultural chemical firm announced plans to cease operations at the site.

From BBC ● Oct. 1, 2026

"Work started early in the morning because the planes took off at first light... and operations usually wrapped up at dusk, making for long, intense days," he said.

From Barron's ● Oct. 1, 2026

A single analysis can require hundreds of billions of floating-point operations, and videos are often processed sequentially.

From Science Daily ● Oct. 1, 2026

I’d been too young when I had my big operations to remember the before-versus-after, the dramatic transformation.

From "Ugly" by Robert Hoge

Related Words

• action
• activity
• affair
• agency
• application
• deal
• effort
• enterprise
• exercise
• force
• movement
• procedure
• process
• service
• transaction
• trip
• use
• work