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

For its lethal injection, Florida uses a combination of a sedative, a paralytic and a drug that stops the heart, the outlet reported, citing the state Department of Corrections. —Lesley Cosme Torres, People.com, 1 Aug. 2025

Edward Zakrzewski, 60, was pronounced dead at 6:12 p.m. at Florida State Prison near Starke after a three-drug injection, which consists of a sedative, a paralytic and a drug that stops the heart, according to the state Department of Corrections. —Landon Mion, FOXNews.com, 1 Aug. 2025

Zakrzewski is set to be executed by lethal injection at 6 p.m. ET on Thursday at the at Florida State Prison in Railford, about 45 miles southwest of Jacksonville. —Amanda Lee Myers, USA Today, 31 July 2025

Offering six months of protection with just two injections per year, Yeztugo stands in stark contrast to existing PrEP regimens, which require a daily pill and quarterly visits for refills and lab monitoring. —Richard Fowler, Forbes.com, 31 July 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