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

Despite being given an injection of serum rushed from state laboratories in Albany, a bronchoscopy procedure to clear the congestion in his lungs, and three blood transfusions, Wallace passed away a few days later, with his wife and two young children at his bedside. —Alan Lightman september 12, Literary Hub, 12 Sep. 2025

Condemned inmates in Utah can opt to die via lethal injection or firing squad. —Amanda Castro joshua Rhett Miller, MSNBC Newsweek, 12 Sep. 2025

Though stratospheric aerosol injection over the poles could potentially cool the lower atmosphere atop the ice caps, the study notes that the aerosols could actually the overlying stratosphere—which could disrupt atmospheric circulation, warming Russia in the winter. —Alec Luhn, Scientific American, 11 Sep. 2025

Wegovy injection pens arranged in Waterbury, Vermont, US, on Monday, April 28, 2025. —Karen Gilchrist,katrina Bishop, CNBC, 10 Sep. 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