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

Nitrite is then swallowed and converted to nitric oxide when passing through low-oxygen regions along the gastrointestinal tract. —New Atlas, 27 July 2025

Your body converts nitrate into nitric oxide, which dilates blood vessels and causes blood pressure levels to drop. —Nancy Lebrun, Verywell Health, 9 July 2025

Erections rely on the bioavailability of nitric oxide and the ability of blood vessels to dilate efficiently. —Ximena Araya-Fischel, Forbes.com, 26 June 2025

They're packed with health-promoting compounds, including nitrites, which the body converts to nitric oxide. —Lindsey Desoto, Verywell Health, 5 June 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)