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

Earlier this year, the Food and Drug Administration issued an advisory warning of the adverse health effects of nitrous oxide use. —Sydney Barragan, Oc Register, 31 Aug. 2025

The child had come to the practice a few months prior, at 3 years old, and Davis had attempted to use nitrous oxide, also known as laughing gas, to perform the procedure. —Deon J. Hampton, NBC news, 27 Aug. 2025

First, Adofo-Mensah traded sulfur dioxide and nitrous oxide. —Alec Lewis, New York Times, 20 Aug. 2025

Induction Cooktop Rentals – Induction cooking does not emit fumes, protecting you and your household from dangerous carbon monoxide, nitrous oxides, and more. —News Release, San Diego Union-Tribune, 15 Aug. 2025

Word History

First Known Use

1798, in the meaning defined above

Rhymes for nitrous oxide

• acetamide
• acetonide
• acidified
• antimonide
• beatified
• benzaldehyde
• borohydride
• chalcogenide
• commodified
• decalcified
• declassified
• disaccharide

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