# operation

/ˌɑpɝˈeɪʃən/ (US) · /ˌɒpəɹˈeɪʃən/ (UK)

Source: https://englishreference.com/word/operation
Updated: 2026-07-22

## Senses

### 1. medical surgery

noun · CEFR B1

a medical procedure where a doctor cuts into a person's body to fix or remove something.

For teachers: a surgical procedure performed by medical professionals to treat a pathological condition or injury.

- He had a minor operation on his knee to repair the damaged tissue.
- The patient underwent a complex five-hour operation to remove the tumor, followed by several weeks of intensive recovery.

### 2. business or activity

noun · CEFR B2

the way a business or organization works and does its daily activities.

For teachers: the functional activities or management of a business, organization, or system.

- The company is moving its main operation to a larger office in the city.
- The logistics operation requires precise coordination between the warehouse staff and the international shipping department.

### 3. military/police plan

noun · CEFR B2

a planned action by the military or police to achieve a specific goal.

For teachers: a coordinated set of actions by military or police forces designed to achieve a strategic objective.

- The police launched a secret operation to catch the thieves.
- The joint military operation was executed with surgical precision, successfully securing the border without any civilian casualties.

### 4. functioning of a machine

noun · CEFR B1

the way a machine or system works when it is turned on.

For teachers: the state of being functional or the specific manner in which a device performs its intended task.

- The manual explains the safe operation of the heating system.
- The engineers monitored the operation of the turbine throughout the night to ensure the vibrations remained within safety limits.

### 5. math/logic process

noun · CEFR B2 · Academic

a mathematical process like adding or subtracting numbers.

For teachers: a mathematical or logical procedure that takes one or more input values to produce a defined output.

- Addition is the first mathematical operation that children learn in school.
- The algorithm performs a complex logical operation on the data set before generating the final report.

## Examples

- The rescue operation saved three people from the mountain.
- The hospital staff prepared the room for a minor operation scheduled for early tomorrow morning.
- The logistics company streamlined its entire operation by implementing a new tracking system that monitors every delivery vehicle in real time.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.