injection

American  

[in-jek-shuhn] / ɪnˈdʒɛk ʃən /

noun

• injections
  plural

1. the act of injecting.

2. something that is injected.

3. a liquid injected into the body, especially for medicinal purposes, as a hypodermic or an enema.

4. state of being hyperemic or bloodshot.

5. Mathematics. a one-to-one function.

6. Also called insertion. Aerospace. the process of putting a spacecraft into orbit or some other desired trajectory.

---

injection British  

/ ɪnˈdʒɛkʃən /

noun

1. fluid injected into the body, esp for medicinal purposes

2. something injected

3. the act of injecting

4. 1. the act or process of introducing fluid under pressure, such as fuel into the combustion chamber of an engine

   2. ( as modifier )

      injection moulding

5. maths a function or mapping for which f( x ) = f( y ) only if x = y See also surjection bijection

---

injection Scientific  

/ ĭn-jĕk′shən /

1. A substance that is introduced into a organism, especially by means of a hypodermic syringe, as a liquid into the veins or muscles of the body.

2. A function that maps each member of one set (the domain) to exactly one member of another set (the range).

3. Compare bijection surjection

---

Other Word Forms

Derived Forms

• reinjection
  noun
• superinjection
  noun
• injective
  adjective
• postinjection
  adjective

Inflected Forms

Nouns

• injections
  plural

Etymology

Origin of injection

First recorded in 1535–45, injection is from the Latin word injectiōn- (stem of injectiō ). See inject, -ion

Explanation

An injection is a shot, or a dose of medicine given by way of a syringe and a needle. When you get jabbed in the arm with a tetanus vaccine, that's an injection. The medical kind of injection forces a small amount of a drug under the skin or directly into a muscle. Other injections are similar in that they involve a liquid being forced by pressure, like the fuel injection in a car, which pushes gasoline directly into the engine. Since the 1600s, injection has been used to mean "forcing a fluid into a body," from the Latin inicere, "to throw in" or "to throw on."

Example Sentences

See Examples For:

injection injections

In the attempted lethal injection of a different inmate in May, a medical professional failed to establish the IV correctly.

From The Wall Street Journal ● Oct. 3, 2026

Lethal injection has proven to be a difficult execution method to get right.

From Salon ● Oct. 3, 2026

Tennessee Department of Correction Commissioner Frank Strada will leave the position this month amid scrutiny over the system’s failed execution by lethal injection of Christa Pike on Wednesday.

From The Wall Street Journal ● Oct. 3, 2026

He still remembers the death of Jonathan Nobles, who was executed by lethal injection in Texas in 1998.

From BBC ● Oct. 2, 2026

She broke open one of the tiny penicillin bottles she often bought when she shopped at a pharmacy, and tried giving my brothers a penicillin injection.

From "Tasting the Sky" by Ibtisam Barakat

Christa Pike, 50, on Wednesday survived two lethal injections of pentobarbital, a drug that suppresses nervous system activity.

From Barron's ● Oct. 4, 2026

The Death Penalty Information Center, a think-tank that does not take a stance on the death penalty, lists 64 botched executions since 1982, 51 of them lethal injections.

From BBC ● Oct. 2, 2026

At the lowest consumer-friendly rung rest affordable fillers and Botox injections.

From Salon ● Oct. 1, 2026

Meta outlined safety measures that direct the agent to disregard prompt injections and limit its access to secrets.

From The Wall Street Journal ● Sep. 29, 2026

I could remotely conceive surprising him once, for an instant, the way his mother had been when she was captured— but to surprise him long enough to give him six consecutive injections?

From "Life of Pi" by Yann Martel

Related Words

• dose
• needle