• synonyms


[in-jek-shuh n]
  1. the act of injecting.
  2. something that is injected.
  3. a liquid injected into the body, especially for medicinal purposes, as a hypodermic or an enema.
  4. state of being hyperemic or bloodshot.
  5. Mathematics. a one-to-one function.
  6. Also called insertion. Aerospace. the process of putting a spacecraft into orbit or some other desired trajectory.
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Origin of injection

First recorded in 1535–45, injection is from the Latin word injectiōn- (stem of injectiō). See inject, -ion
Related formspost·in·jec·tion, adjectivere·in·jec·tion, nounsu·per·in·jec·tion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for postinjection


  1. fluid injected into the body, esp for medicinal purposes
  2. something injected
  3. the act of injecting
    1. the act or process of introducing fluid under pressure, such as fuel into the combustion chamber of an engine
    2. (as modifier)injection moulding
  4. maths a function or mapping for which f(x) = f(y) only if x = ySee also surjection, bijection
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Derived Formsinjective, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for postinjection



"forcing a fluid into a body" (with a syringe, etc.), early 15c., from Middle French iniection (14c.) or directly from Latin iniectionem (nominative iniectio), noun of action from past participle stem of inicere (see inject).

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Online Etymology Dictionary, © 2010 Douglas Harper

postinjection in Medicine


  1. The act of injecting a substance into a tissue, vessel, canal, or organ.
  2. Something that is injected, especially a dose of liquid medicine injected into the body.
  3. Congestion or hyperemia.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

postinjection in Science


  1. A substance that is introduced into a organism, especially by means of a hypodermic syringe, as a liquid into the veins or muscles of the body.
  2. A function that maps each member of one set (the domain) to exactly one member of another set (the range). Compare bijection surjection.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.