injection

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.

Pronunciation

• IPA^(key): /ɪnˈd͡ʒɛk.ʃən/

• Audio (Southern England):

  (file)

• Hyphenation: in‧jec‧tion
• Rhymes: -ɛkʃən

Noun

injection (countable and uncountable, plural injections)

1. The act of injecting, or something that is injected.
   • 2010, Paul Shreve, David W. Townsend, Clinical PET-CT in Radiology: Integrated Imaging in Oncology, →ISBN, page 78:

     For some indications in PET imaging, it is necessary for radiopharmaceutical injections to be administered contralaterally or pedally to the disease process

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.

   Synonym: injective function

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.
   • 2015, Henry L. Richter, America's Leap Into Space:

     It had been determined that one of the whip turnstile antennas had broken off from Explorer 1 shortly after injection into orbit, so these were eliminated.

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.

See also

References

• injection on Wikipedia.Wikipedia

Etymology

Borrowed from Latin iniectiōnem.

Pronunciation

• IPA^(key): /ɛ̃.ʒɛk.sjɔ̃/

• Audio:

  (file)

Noun

injection f (plural injections)

1. injection

Further reading

• “injection”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.