in·​jec·​tion | \ in-ˈjek-shən How to pronounce injection (audio) \

Definition of injection

1a : an act or instance of injecting
b : the placing of an artificial satellite or a spacecraft into an orbit or on a trajectory also : the time or place at which injection occurs
2 : something (such as a medication) that is injected
3 : a mathematical function that is a one-to-one mapping — compare bijection, surjection

Examples of injection in a Sentence

The medicine cannot be taken orally; it must be given by injection. an injection of a painkiller The struggling company needed an injection of cash.
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Recent Examples on the Web

There are drug injections from the couple’s doctor, designed to keep them going during grueling diplomatic trips. Alissa Wilkinson, Vox, "The Kennedy family built up a public mythology. TV and movies are taking it apart.," 9 Apr. 2018 On Tuesday, Illinois Governor Bruce Rauner signed an ammendment to a law that will equip police officers with epinephrine auto-injection — more commonly known as the allergy attack antitdote, EpiPen. Serena Sonoma, Teen Vogue, "Annie LeGere Law Allows Illinois Police to Carry EpiPens," 1 Aug. 2018 The Ascent’s boxer engine incorporates direct injection of regular 87-octane gas, turbocharging and intercooling to deliver up to 260 horsepower at 5,600 rpm. Jeff Yip, Houston Chronicle, "Newly arrived 2019 Subaru Ascent fills three-row midsize SUV niche," 24 June 2018 The bill also adds incentive for doctors to use post-surgical injections as a pain-treatment alternative to opioids., "House approves bill expanding treatment for opioid abuse," 22 June 2018 Needle exchanges offer sterile drug-injection equipment in exchange for used equipment. Terry Demio,, "No condoms at NKY needle exchanges, says Catholic health system St. Elizabeth," 27 Mar. 2018 Baxter bought a medicine-injection supplier in December and Almeida says there could be more buying activity in 2018. Susie Gharib, Fortune, "This CEO Believes That Innovation and Culture Are One and the Same," 14 Feb. 2018 Different fuel-injection architectures call for different diagnostics; the factory manual will have those specific to your car. Mike Allen, Popular Mechanics, "Fixing a Car that Won't Start," 9 Jan. 2017 Photo: Dana Verkouteren/Associated Press Justice Kavanaugh remained silent while Mr. Hochman debated the fine points of lethal injection with other justices and argued the feasibility of killing him with poison gas. Jess Bravin, WSJ, "Kavanaugh Questions Death-Penalty Method in Missouri Case," 6 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'injection.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of injection

15th century, in the meaning defined at sense 1a

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Last Updated

14 Mar 2019

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Time Traveler for injection

The first known use of injection was in the 15th century

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More Definitions for injection



English Language Learners Definition of injection

: the act or process of forcing a liquid medicine or drug into someone or something by using a special needle
: the act or process of forcing a liquid into something
: the addition of something (such as money) that is needed to support something


in·​jec·​tion | \ in-ˈjek-shən How to pronounce injection (audio) \

Kids Definition of injection

: an act or instance of forcing a fluid (as a medicine) into a part of the body by using a special needle Insulin can be given by injection.


in·​jec·​tion | \ in-ˈjek-shən How to pronounce injection (audio) \

Medical Definition of injection

1a : the act or an instance of injecting a drug or other substance into the body
b : a solution (as of a drug) intended for injection (as by catheter or hypodermic syringe) either under or through the skin or into the tissues, a vein, or a body cavity
c : an act or process of injecting vessels or tissues also : a specimen prepared by injection
2 : the state of being injected : congestion — see circumcorneal injection

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More from Merriam-Webster on injection

Rhyming Dictionary: Words that rhyme with injection

Spanish Central: Translation of injection

Nglish: Translation of injection for Spanish Speakers

Britannica English: Translation of injection for Arabic Speakers Encyclopedia article about injection

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a shady place in a garden or forest

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