nitrous oxide

noun

: a colorless gas N2O that when inhaled produces loss of sensibility to pain preceded by exhilaration and sometimes laughter, that is used especially as an anesthetic in dentistry and as a fuel, and that is an atmospheric pollutant and greenhouse gas produced by combustion

called also laughing gas

compare nitric oxide

Examples of nitrous oxide in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Connelly allegedly supplied the rapper with nitrous oxide and encouraged unsupervised self-administration while ignoring clear adverse neurological and behavioral signs apparent in the patient, the letter states. Kevin Dolak, HollywoodReporter, 1 May 2025 The science of nitrous oxide: short high, long-term risks Nitrous oxide works by inhibiting NMDA receptors in the brain, which play a key role in how our brain processes signals related to pain and memory. Ella Jeffries, Smithsonian Magazine, 8 Apr. 2025 Does not compute: House Republicans dropped legislation that would block the Biden administration from factoring in the social cost of carbon, methane, nitrous oxide, or any other greenhouse gas metric in the rulemaking process. Daniel Moore, Axios, 15 Oct. 2024 While nitrous oxide has legitimate medical uses, recreational use carries significant risks: Oxygen deprivation: Inhaling nitrous oxide displaces oxygen in the lungs, leading to hypoxia, or oxygen deprivation. Marley Malenfant, Austin American-Statesman, 25 Sep. 2024 See All Example Sentences for nitrous oxide

Word History

First Known Use

1798, in the meaning defined above

Time Traveler
The first known use of nitrous oxide was in 1798

Browse Nearby Words

Cite this Entry

“Nitrous oxide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nitrous%20oxide. Accessed 21 May. 2025.

Kids Definition

nitrous oxide

noun
: a colorless gas that when inhaled causes loss of the ability to feel pain and sometimes produces laughter and is used especially in dentistry

called also laughing gas

Medical Definition

nitrous oxide

noun
: a colorless gas N2O that when inhaled produces loss of sensibility to pain preceded by exhilaration and sometimes laughter and is used especially as an anesthetic in dentistry

called also laughing gas

More from Merriam-Webster on nitrous oxide

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!