injection

noun

in·​jec·​tion in-ˈjek-shən 

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

During the May 6 episode of his The Three Questions podcast, the comedian and longtime sidekick to Conan O’Brien spoke to Modern Family alum Eric Stonestreet about the use of GLP-1 weight-loss injections. —Vanessa Etienne, People.com, 6 May 2025

The largely receptive crowd often cheered at the scattershot injection of issues from the price of eggs to transgender rights, a microcosm of an era when even the pablum of a graduation speech cannot escape the politics of the moment. —Erica L. Green, New York Times, 2 May 2025

There was also glutamine, which is said to support gut health and absorption; glutathione for its supposed antioxidant action, immune support and hyperpigmentation benefits; and a placenta injection, which I was told helps with skin regeneration. —Parizaad Khan Sethi, Allure, 2 May 2025

The Florida Department of Corrections will execute Hutchinson by lethal injection. —James Powel, USA Today, 2 May 2025

Word History

First Known Use

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

Phrases Containing injection

• fuel injection
• hypodermic injection
• injection molding

Rhymes for injection

• abjection
• advection
• affection
• bijection
• bisection
• collection
• complexion
• confection
• connection
• connexion
• convection
• correction

Kids Definition

injection

noun

in·​jec·​tion in-ˈjek-shən 

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 

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