in·jec·tion | \in-ˈjek-shən \

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

Reserpine injections immobilized rabbits, but no one understood why. Denise Gellene,, "Arvid Carlsson, 95; discovered a treatment for Parkinson’s," 2 July 2018 In severe plantar fasciitis cases or those that haven’t responded to earlier treatments, anti-inflammatory injections may help. Markham Heid, Time, "You Asked: What’s the Best Way to Treat Plantar Fasciitis?," 27 June 2018 For pain management, Purtill said weight loss can be paired with injections, physical therapy, and pain medications such as Tylenol or other anti-inflammatory drugs. Mari A. Schaefer,, "Got knee pain? Researchers pinpoint percentage of weight loss needed to reduce discomfort," 18 June 2018 After getting the antibody injections, that burden lifted. Emily Underwood, Science | AAAS, "Will antibodies finally put an end to migraines?," 18 May 2018 The push for change comes because lethal injection, introduced 40 years ago as more efficient and humane than the electric chair or gas chamber, has not met that promise. Author: Denise Grady, Jan Hoffman, Anchorage Daily News, "States turn to an unproven method of execution: nitrogen gas," 8 May 2018 Showing no signs of an achy back that has required constant treatment and a few injections, Hill steadied a teetering offense that watched an 11-point halftime lead quickly turn into a one-point edge. Zachariah Durr,, ""More Tristan!" cry Cavs fans as they "Sound Off" on Game 7's win over Pacers (VIDEO)," 29 Apr. 2018 Corey Kluber received an injection in his right knee that will force the Indians ace to miss the All-Star Game., "Knee surgery scheduled for Lonzo Ball," 14 July 2018 Kluber, 32, received an injection in his right knee Friday. Stephen Ruiz,, "Zack Greinke added to NL all-star roster while Corey Kluber won't pitch for AL," 13 July 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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Statistics for injection

Last Updated

10 Oct 2018

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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 \

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 \

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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Comments on injection

What made you want to look up injection? Please tell us where you read or heard it (including the quote, if possible).


not any or not one

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