injection

noun

in·​jec·​tion in-ˈjek-shən How to pronounce injection (audio)
Synonyms of injectionnext
1
a
: 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.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In recent years, Idaho, Utah and South Carolina have been among the states to embrace the firing squad as a potential means of execution as lethal injections fall out of favor. — Michael Ruiz, FOXNews.com, 11 Oct. 2026 Trump’s approval of Hasan’s execution last Friday came days after a botched lethal-injection execution in Tennessee. — Lorraine Ali, Los Angeles Times, 10 Oct. 2026 That's out of nearly 190,000 reports made about the drug over that period, most of which included minor gastrointestinal issues, dosing errors or injection site redness. — Yuki Noguchi, NPR, 10 Oct. 2026 Treatment for varicose veins typically involves a minimally invasive procedure to shut or seal off the problem veins, using either heat (thermal ablation), a foam or liquid injection (chemical ablation) or a specialized type of glue. — Erica Sloan, Washington Post, 10 Oct. 2026 See All Example Sentences for injection

Word History

First Known Use

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

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

Phrases Containing injection

Rhymes for injection

See All Rhymes for injection

Browse Nearby Words

injectant
injection
injection gneiss
See all Nearby Words

Cite this Entry

“Injection.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/injection. Accessed 14 Oct. 2026.

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Kids Definition

injection

noun
in·​jec·​tion in-ˈjek-shən How to pronounce injection (audio)
1
: an act or instance of injecting
2
: something (as a medical drug) that is injected

Medical Definition

injection

noun
in·​jec·​tion in-ˈjek-shən How to pronounce injection (audio)
1
a
: 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

More from Merriam-Webster on injection

Thesaurus: All synonyms and antonyms for injection

Britannica.com: Encyclopedia article about injection

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