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

These fertilizers release nitrous oxide, a potent greenhouse gas. —Marta Zaraska, Smithsonian Magazine, 1 Apr. 2025

Atmospheric concentrations of carbon dioxide, methane and nitrous oxide were at the highest levels in the last 800,000 years. —Jade Walker, CNN, 19 Mar. 2025

The ingredient list also usually includes dimethyl silicone (anti foaming agent) and a propellant gas such as nitrous oxide, carbon dioxide, or propane, which are deemed safe to use by the FDA1. —Katlyn Moncada, Better Homes & Gardens, 19 Mar. 2025

People who abuse nitrous oxide often lose their balance and coordination. —Stephanie Brown, Verywell Health, 24 Jan. 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