English Reference
noun

adrenaline

n.
US /əˈdɹɛnəɫən/ UK /ɐdɹˈɛnəlˌɪn/ adren·a·line

  1. 01 B2 Upper Intermediate Technical Medicine

    a chemical in your body that makes your heart beat faster when you are stressed or excited.

    the hormone epinephrine, secreted by the adrenal glands, which increases cardiac output and raises glucose levels in the blood.

    Simple

    The doctor gave him a shot of adrenaline to stop the allergic reaction.

    In context

    Adrenaline is released into the bloodstream during the fight-or-flight response, preparing the body for immediate physical exertion.

    Usage

    Often used as an uncountable noun in medical contexts.

  2. 02 B2 Upper Intermediate

    a feeling of great energy and excitement.

    a state of heightened physiological arousal or intense excitement.

    Simple

    I felt a rush of adrenaline as I stood at the top of the mountain.

    In context

    Extreme sports enthusiasts often seek the adrenaline hit that comes from activities like skydiving or rock climbing.

    Usage

    Commonly used in the phrase 'adrenaline rush'.

I think about this carefully, trying to identify the fizzing adrenaline rush inside of me.

The Guardian· 23 Aug 2026

But then I was on adrenaline thinking: 'I have to keep these people safe'.

BBC News· 22 Aug 2026

From adrenal + -ine, coined by Japanese chemist Takamine Jōkichi in 1901.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated