nitric oxide

noun

Definition of nitric oxide

: 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

Recent Examples of nitric oxide from the Web

The paper also contains a line that the vampire Master didn't considered: Big nuke blasts will block sunlight but the temperature extremes also cause a lot of nitric oxides to enter the atmosphere.

— joe pappalardo, Popular Mechanics, "Hollywood Has No Idea How Nukes Work," 2 Apr. 2018
Essentially, nitric oxide is a gas that your body produces to help cells communicate better with one another.

— emily abbate, GQ, "A Complete Guide to Pre-Workout Supplements," 4 Apr. 2018
Apparently, exposure to sunlight can also affect levels of nitric oxide in your body, which may have interesting implications for both health and sports performance.

— alex hutchinson, Outside Online, "Sunlight May Be the Next Beet Juice," 22 Mar. 2018
And a 1997 study in The Lancet showed that on the skin, nitrite in saliva is converted to nitric oxide, which is antimicrobial.

— erika engelhaupt, National Geographic, "How Dog and Cat 'Kisses' Can Turn Deadly," 24 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nitric oxide.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of nitric oxide

1789

in the meaning defined above

See Words from the same year

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Medical Dictionary

nitric oxide

noun

medical Definition of nitric oxide

: 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)