nitrogen oxide


Definition of nitrogen oxide 

: any of several oxides of nitrogen most of which are produced in combustion and are considered to be atmospheric pollutants: such as

a : nitric oxide

b : nitrogen dioxide

c : nitrous oxide

Examples of nitrogen oxide in a Sentence

Recent Examples on the Web

There are two main categories of air pollution: First, there's ground-level ozone, which is a product of nitrogen oxides and volatile organic compounds that have been exposed to heat and sunlight. Korin Miller, SELF, "How to Stay Safe When Your City’s Air Quality Is Dangerous," 21 Aug. 2018 An environmental group filed the suit arguing that measures taken so far by Düsseldorf and Stuttgart are inadequate, exposing citizens to nitrogen oxide emissions that regularly exceed legal limits. The New York Times, New York Times, "A Short Market Week, Walmart Earnings and Warren Buffett’s Letter," 18 Feb. 2018 The study of on-road performance found that one emitted up to 35 times the allowable amount of toxic nitrogen oxide. Washington Post, "US indictment alleges top VW exec knew of emissions cheating," 5 May 2018 The study said pollution levels from nitrogen oxide fell 7% from 2005 to 2009, but only dropped 1.7% from 2011 to 2015. Doyle Rice, USA TODAY, "The USA's long battle against air pollution isn't over yet, as air quality improvements are slowing down," 30 Apr. 2018 Under actual driving conditions, the vehicles produced much more lung-damaging nitrogen oxides than allowed by law. Jack Ewing, New York Times, "Volkswagen Agrees to $1.2 Billion German Fine in Emissions-Cheating Scheme," 13 June 2018 It is intended to mitigate emissions of harmful air pollutants called nitrogen oxides from the polluting diesel vehicles, many of which have been taken off the road after Volkswagen bought them back. Kate Galbraith, San Francisco Chronicle, "California regulators approve $423 million for clean transportation," 25 May 2018 State officials figure the Volkswagen diesel emissions testing scandal added an extra 10,000 tons of noxious nitrogen oxide to California's air. Russ Mitchell,, "VW funds from diesel scandal will pay for zero-emission buses, trucks in California," 26 May 2018 Out on the open road, a different engine management map would be in charge, resulting in high levels of nitrogen oxide (NOx) pollutants coming out in the exhaust. Jonathan M. Gitlin, Ars Technica, "Bosch might just have solved the problem of diesel NOx emissions," 27 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nitrogen 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 nitrogen oxide

1868, in the meaning defined above

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Last Updated

12 Nov 2018

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The first known use of nitrogen oxide was in 1868

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