nitric oxide


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

Examples of nitric oxide in a Sentence

Recent Examples on the Web Actinomyces and Rothia—which play a key role in turning food’s nitrate into nitric oxide that helps regulate blood pressure—showed up in just about every sample. Popular Science, "The world’s most diverse group of bacteria lives inside your mouth," 5 Jan. 2021 Laughter releases nitric oxide, a chemical that relaxes blood vessels, reduces blood pressure and decreases clotting, Miller said. Richard Schiffman, Star Tribune, "No joke – laughter is healthy," 9 Oct. 2020 Toward the beginning of August, the teen's condition improved after she was given nitric oxide and positioned on her stomach, a technique referred to as proning. Joelle Goldstein,, "14-Year-Old Girl Survives Coronavirus After 57 Days in Calif. Hospital: 'COVID Is Not a Joke'," 18 Sep. 2020 According to information on the web site, at 9 a.m. Wednesday, MAML #1 measured 2.27 parts per million of methane, 144.2 parts per billion of nitric oxide, 40.1 ppb of nitrogen dioxide, and 184.8 ppb of nitrogen oxide, a precursor of ozone. Mark Schleifstein,, "Louisiana moves two mobile air monitoring labs to Lake Charles," 3 Sep. 2020 Authorities warned that the smoke could contain chlorine, nitric oxide and other toxins used in industrial and commercial disinfectants and for swimming pool maintenance. Washington Post, "Laura devastated a narrow path north of the Gulf Coast, sparing some population centers," 27 Aug. 2020 Some doctors are experimenting with adding nitric oxide to the mix, to help improve blood flow and oxygen to the least damaged parts of the lungs. Mike Stobbe, The Denver Post, "Some doctors moving away from ventilators for coronavirus patients," 11 Apr. 2020 Particulates pollution, nitric oxide and nitrogen dioxide also decreased this month around metro Denver — by up to 50% in some areas — compared with concentrations a year ago, the data shows. Bruce Finley, The Denver Post, "Colorado sees “significant declines” in air pollution as coronavirus ramps down driving, industrial activity," 5 Apr. 2020 Other types of cells in the body, including circulating white blood cells and tissue macrophages, produce nitric oxide for antimicrobial purposes. The Conversation, oregonlive, "The science behind why this is the safest way to breathe to avoid coronavirus," 19 June 2020

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.

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First Known Use of nitric oxide

1789, in the meaning defined above

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Time Traveler for nitric oxide

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The first known use of nitric oxide was in 1789

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Statistics for nitric oxide

Last Updated

11 Jan 2021

Cite this Entry

“Nitric oxide.” Dictionary, Merriam-Webster, Accessed 20 Jan. 2021.

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More Definitions for nitric oxide

nitric oxide


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)

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