infusion

American  

[in-fyoo-zhuhn] / ɪnˈfyu ʒən /

noun

1. the act or process of infusing.

2. something that is infused.

3. a liquid extract, as tea, prepared by steeping or soaking.

4. Pharmacology.

   1. the steeping or soaking of a crude drug in water.

   2. the liquid so prepared.

5. Medicine/Medical.

   1. the introduction of a saline or other solution into a vein.

   2. the solution used.

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infusion British  

/ ɪnˈfjuːʒən, ɪnˈfjuːsɪv /

noun

1. the act of infusing

2. something infused

3. an extract obtained by soaking

4. med introduction of a liquid, such as a saline solution, into a vein or the subcutaneous tissues of the body

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Other Word Forms

• infusive
  adjective
• reinfusion
  noun

Etymology

Origin of infusion

1400–50; late Middle English < Latin infūsiōn- (stem of infūsiō ). See infuse, -ion

Explanation

The most common example of an infusion you are likely to encounter in your daily life is your morning cup of coffee. An infusion is the creation of a new substance by steeping another substance in a liquid, usually water. Infusion is often misused with transfusion, which has a slightly different meaning. A transfusion, as in a blood transfusion, is the simple addition of one substance to another, without the creation of something new. But a drip feed of medicine, for example, is technically an infusion as it alters the state of the blood. See, you’re halfway to becoming a doctor (or at least a linguist) simply by reading this site.

Example Sentences

The most common adverse side effects were mostly “low-grade” rash, diarrhea, fatigue, and infusion reaction.

From Barron's • May 11, 2026

Since 2015, NHS patients have received the world's best-selling drug through a drip – or intravenous infusion – which can take more than an hour to administer in hospital.

From BBC • May 3, 2026

The airline has been in talks with the U.S. government to secure a $500-million cash infusion in exchange for a majority stake in the company.

From Los Angeles Times • May 1, 2026

Then Hubbie went to the infusion center for an 11:30 a.m. infusion appointment, which began at approximately 12:35 p.m., again with no explanation for the delay.

From MarketWatch • May 1, 2026

This held tea—not true tea, which they’d run out of long ago, but an herbal infusion to help shake off the lull—and biscuits, since Sarai always slept through lunch.

From "Strange the Dreamer" by Laini Taylor