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

Florida’s lethal injections use a sedative, a paralytic and a drug that stops the heart, according to the Department of Corrections. —Greg Wehner, FOXNews.com, 19 Dec. 2025

They were widely criticized for being unflattering, particularly a close-up on Karoline Leavitt that seemed to show fresh filler injection sites around her lips. —Mary Walrath-Holdridge, USA Today, 19 Dec. 2025

Florida executions are done via lethal injection using a sedative, a paralytic and a drug that stops the heart, per the state's Department of Corrections. —Madison E. Goldberg, PEOPLE, 19 Dec. 2025

While Eli Lilly’s pill appears to cause less weight loss overall than existing injections, Thursday’s results highlight its potential role as a needle-free maintenance treatment in the blockbuster GLP-1 market. —Annika Kim Constantino, CNBC, 18 Dec. 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