nitric oxide

noun

: a colorless poisonous gas NO formed by oxidation of nitrogen or ammonia that is present in the atmosphere and also in mammals where it is synthesized from arginine and oxygen and acts as a vasodilator and as a mediator of cell-to-cell communication (as between nerve cells) compare nitrous oxide

Examples of nitric oxide in a Sentence

Recent Examples on the Web

May Improve Athletic Performance Dark chocolate contains compounds that raise nitric oxide in the blood. —Ann Pietrangelo, Verywell Health, 14 Apr. 2025

But testing options have long been limited: Typically, doctors either draw blood to measure levels of immune cells or antibodies, or have children breathe into a mouthpiece to measure the nitric oxide in their breath. —Aria Bendix, NBC News, 2 Jan. 2025

One reason for this is that estrogen helps keep blood vessels flexible and supports the production of nitric oxide, a molecule that allows vessels to relax and maintain healthy blood flow. —Matthew Nudy, The Conversation, 4 Apr. 2025

Summary Nitrate supplements raise your body's levels of nitric oxide, which is an important chemical messenger in the body. —Melissa Nieves, Verywell Health, 2 Apr. 2025

Word History

First Known Use

1789, in the meaning defined above

Rhymes for nitric oxide

• acetamide
• acetonide
• acidified
• antimonide
• beatified
• benzaldehyde
• borohydride
• chalcogenide
• commodified
• decalcified
• declassified
• disaccharide

Medical Definition

nitric oxide

noun

: a poisonous colorless gas NO that occurs as a common air pollutant formed by the oxidation of atmospheric nitrogen and that is also formed by the oxidation of arginine in the mammalian body where it acts as a mediator of intracellular and intercellular communication regulating numerous biological processes (as vasodilation and neurotransmission)