# injection

> English word · Noun · IPA /ɪnˈd͡ʒɛk.ʃən/ · frequency rank #7,238

## Definitions
1. The act of injecting, or something that is injected.
2. A specimen prepared by injection.
3. A morphism from either one of the two components of a coproduct to that coproduct.
4. The act of inserting materials like concrete grout or gravel by using high pressure pumps.
5. The supply of additional funding to a person or a business.
6. A relation on sets (X,Y) that associates each element of Y with at most one element of X.
7. The insertion of program code into an application, URL, hardware, etc.; especially when malicious or when the target is not designed for such insertion.
8. The act of putting a spacecraft into a particular orbit, especially for changing a stable orbit into a transfer orbit, e.g. trans-lunar injection.
9. A function that maps distinct x in the domain to distinct y in the codomain; formally, a f: X → Y such that f(a) = f(b) implies a = b for any a, b in the domain.
10. Something injected subcutaneously, intravenously, or intramuscularly by use of a syringe and a needle.
11. Congestion (of a body part, with blood or other fluid), such as hyperemia.
12. Fuel injection: the pressurized introduction of fuel into a cylinder.
13. The act of throwing cold water into a condenser to produce a vacuum.
14. The cold water thrown into a condenser to produce a vacuum.

## Etymology
Borrowed from Middle French injection, from Latin iniectio. The mathematical sense is from French injection, introduced by Nicolas Bourbaki in their treatise Éléments de mathématique. Equivalent to inject + -ion.

## Easily confused with
- **injector** (https://plainspell.com/en/vs/injection-vs-injector)
- **intention** (https://plainspell.com/en/vs/injection-vs-intention)
- **invention** (https://plainspell.com/en/vs/injection-vs-invention)
- **insertion** (https://plainspell.com/en/vs/injection-vs-insertion)
- **inspection** (https://plainspell.com/en/vs/injection-vs-inspection)
- **injections** (https://plainspell.com/en/vs/injection-vs-injections)
- **injunction** (https://plainspell.com/en/vs/injection-vs-injunction)
- **inaction** (https://plainspell.com/en/vs/inaction-vs-injection)
- **infection** (https://plainspell.com/en/vs/infection-vs-injection)
- **induction** (https://plainspell.com/en/vs/induction-vs-injection)
- **inception** (https://plainspell.com/en/vs/inception-vs-injection)
- **ingestion** (https://plainspell.com/en/vs/ingestion-vs-injection)
- **inflection** (https://plainspell.com/en/vs/inflection-vs-injection)

## Common misspellings (14)
`ijnection`, `inejction`, `injcetion`, `injecction`, `injeciton`, `injecsion`, `injectino`, `injectionn`, `injectoin`, `injecttion`, `injetcion`, `injjection`, `innjection`, `nijection`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/injection