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 most consequential thing to happen to the American food system in the past two years arrived as a weekly injection. —Tenzin Seldon, Fortune, 21 June 2026

Scotto highlighted that Kinetik has purpose-built its system for sour gas handling, giving it an edge over new competitors that may face permitting delays of at least three years to build acid gas injection wells. —Tipranks.com Staff, CNBC, 21 June 2026

Will Smith to get injection for neck Catcher Will Smith (stiff neck) will get an injection to address his neck injury, manager Dave Roberts said. —Maddie Lee, Los Angeles Times, 20 June 2026

This capital injection will fund the completion of an assembly facility near Portland, Oregon, and accelerate a pilot deployment in the northern Pacific Ocean later this year. —Aman Tripathi, Interesting Engineering, 19 June 2026

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