Definition of "injection" in English

noun

1. The act of injecting, or something that is injected.

2. A specimen prepared by injection.

3. (category theory) A morphism from either one of the two components of a coproduct to that coproduct.

4. (construction) The act of inserting materials like concrete grout or gravel by using high pressure pumps.

5. (figuratively) The supply of additional funding to a person or a business.

   • The troubled business received a much-needed cash injection.

6. (mathematics) A relation on sets (X,Y) that associates each element of Y with at most one element of X.

7. (computer security) The insertion of program code into an application, URL, hardware, etc.; especially when malicious or when the target is not designed for such insertion.

   • a SQL injection exploit allowing a malicious user to modify a database query

8. (space science) 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. (set theory) 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. (medicine) Something injected subcutaneously, intravenously, or intramuscularly by use of a syringe and a needle.

11. (medicine) Congestion (of a body part, with blood or other fluid), such as hyperemia.

    • conjunctival injection

12. (internal combustion engines) Fuel injection: the pressurized introduction of fuel into a cylinder.

    • direct injection
    • tuned port injection

13. (steam engines) The act of throwing cold water into a condenser to produce a vacuum.

14. (steam engines) The cold water thrown into a condenser to produce a vacuum.