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

The cost of injection or vial medications (such as Ozempic, Zepbound and Wegovy) are not included in the membership and vary on your insurance coverage, and patients also have the option to pay with cash ($349 to $1,000 per month; learn more at ro.co. —Danielle Directo-Meston, HollywoodReporter, 25 Aug. 2025

Stewart received a cortisone injection and platelet-rich plasma treatment in his shoulder. —Bill Plunkett, Oc Register, 23 Aug. 2025

Lawyers for Idaho’s longest-serving death row prisoner are renewing their efforts to spare him from execution after the state failed last year to put him to death by lethal injection. —Kevin Fixler, Idaho Statesman, 22 Aug. 2025

While the death penalty is legal in Arkansas, no one has been sentenced to death since 2018, and the state hasn't executed anyone since 2017, when state officials used lethal injections to execute four convicts within the period of a week just before the drugs used expired. —Arkansas Online, 21 Aug. 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