adrenaline

American  

[uh-dren-l-in, -een] / əˈdrɛn l ɪn, -ˌin /

noun

1. Biochemistry. epinephrine.

2. the feeling of excitement, alertness, and intensity caused by the release of epinephrine in the body.

   For adventure seekers, there are ungroomed, off-piste routes with deep snow offering lots and lots of adrenaline.

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adrenaline British  

/ əˈdrɛnəlɪn /

noun

1. US name: epinephrine.  a hormone that is secreted by the adrenal medulla in response to stress and increases heart rate, pulse rate, and blood pressure, and raises the blood levels of glucose and lipids. It is extracted from animals or synthesized for such medical uses as the treatment of asthma. Chemical name: aminohydroxyphenylpropionic acid; formula: C 9 H 13 NO 3

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adrenaline Scientific  

/ ə-drĕn′ə-lĭn /

1. See epinephrine

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adrenaline Cultural  

1. A hormone secreted by the adrenal glands that helps the body meet physical or emotional stress (see endocrine system).

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Discover More

Figuratively, the term adrenaline is used in speaking of a high state of excitement: “When the race began, the adrenaline really started pumping.”

Adrenaline plays a very large role in the fight or flight reaction, which refers to the various processes that occur within the body when it is confronted with some form of mental or physical stress.

Etymology

Origin of adrenaline

First recorded in 1900–05; adrenal + -ine ¹

Compare meaning

How does adrenaline compare to similar and commonly confused words? Explore the most common comparisons:

• epinephrine vs. adrenaline
• noradrenaline vs. adrenaline

Explanation

If you've ever been in a car that screeched to a stop, barely avoiding an accident, you probably felt a surge of adrenaline that left your heart pounding. Adrenaline is a hormone that's released in response to stressful situations. Adrenaline was named after the gland in the human body that releases it, the adrenal gland. The body secretes adrenaline when danger or stress is present, as a kind of safety measure; when adrenaline is released in your body, you feel your heart beat faster and a sudden rush of energy which might give you the strength to fight off an attacker or flee a dangerous animal.

Example Sentences

The actress plays an outdoors-loving adrenaline junkie harassed by a group of hunters in director Baltasar Kormákur’s spectacular, unsettling film.

From The Wall Street Journal • Apr. 23, 2026

Katy administered an adrenaline pen and Molly was taken to hospital where she later recovered, but Katy said the fear had never left her.

From BBC • Apr. 23, 2026

Glover, born in 1976 in Pomona, was an adrenaline junkie who dreamed of being everything from a stuntman to a race car driver.

From Los Angeles Times • Mar. 30, 2026

Several times while training for Ironman triathlons, I’ve crashed my bike and jumped right back up—there was so much adrenaline flowing that I didn’t feel pain in the moment.

From The Wall Street Journal • Mar. 1, 2026

A shot of adrenaline burst through him, giving him new energy.

From "Earthquake Terror" by Peg Kehret