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

Saoirse can’t bear to think of her youngest daughter’s face when the public health nurse cooed, tickled her thighs, and then surprised her with an injection in the arm. —Literary Hub, 23 Mar. 2026

Sun Pharmaceutical, one of the top generics manufacturers in the world, on Saturday launched a generic semaglutide for as low as 750 rupees ($8) for a weekly injection, or about 3,400 rupees per month. —Priyanka Salve,elsa Ohlen, CNBC, 23 Mar. 2026

Depending on dose strength, Novo Nordisk's noninsurance, cash price for Wegovy injections range from $199 to $349 a month. —Christopher Rowland The Washington Post, Arkansas Online, 21 Mar. 2026

The new lethal injection protocol uses the single drug pentobarbital, as opposed to three drugs under the previous method. —Amanda Lee Myers, USA Today, 21 Mar. 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