Definition

Noun: 1. A hormone and neurotransmitter: A substance produced by the adrenal glands, especially in response to stress, fear, or excitement. It prepares the body for rapid action by increasing heart rate, blood pressure, and energy supplies. 2. A feeling of excitement or energy: Used informally to describe a rush of excitement or heightened energy.

Usage and Examples

• Noun (Biological Substance):
  • The sudden scare caused a surge of adrenaline.
  • Adrenaline is released into the bloodstream during the "fight-or-flight" response.
• Noun (Informal: Feeling):
  • She gets a real adrenaline rush from skydiving.
  • The race was pure adrenaline from start to finish.

Advanced Usage

• "Adrenaline junkie": (idiomatic) A person who seeks out thrilling, dangerous activities to experience the feeling caused by adrenaline.
  • He's a total adrenaline junkie, always looking for the next extreme sport.

Variants and Related Words

• Adrenalin: A former trademark name for the hormone, now often used interchangeably with "adrenaline," especially in medical contexts.
• Epinephrine: The official scientific and medical name for the hormone adrenaline.
• Adrenergic: (Adjective) Relating to or denoting nerve cells that use adrenaline, noradrenaline, or a similar substance as a neurotransmitter.

Synonyms

• Epinephrine (scientific synonym)
• Fight-or-flight hormone (descriptive synonym)

Related Idioms and Phrases

• Adrenaline rush / surge / pump: A sudden, strong feeling of excitement and energy caused by the release of adrenaline.
  • Finishing the marathon gave her an incredible adrenaline rush.

Noun

1. a catecholamine secreted by the adrenal medulla in response to stress (trade name Adrenalin); stimulates autonomic nerve action