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

Even more remarkably, ten of these individuals were able to discontinue daily insulin injections entirely. —William A. Haseltine, Forbes.com, 12 Aug. 2025

If your loved one faints from hypoglycemia, give them a glucagon injection according to their healthcare provider’s instructions. —Carrie Madormo, Verywell Health, 11 Aug. 2025

Adding to Wednesday’s discomfort — which isn’t nearly as funny this time around — is the injection of the entire Addams clan into the Nevermore scene. —Daniel Fienberg, HollywoodReporter, 6 Aug. 2025

Investigators said Hill then spent the money on personal expenses like rental cars, hotel rooms and vitamin injections, none of which benefited the woman. —Cristóbal Reyes, The Orlando Sentinel, 6 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