Inorganic compound, one of the oxides of nitrogen. A colourless gas with a pleasantly sweetish odour and taste, it has an analgesic effect when inhaled; it is used as an anesthetic (often called just “gas”) in dentistry and surgery. This effect is preceded by mild hysteria, sometimes with laughter, hence the name laughing gas. It is also used as a propellant in food aerosols and as a leak detector.

Learn more about nitrous oxide with a free trial on Britannica.com.