Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, nitro, or nos is a chemical compound, an oxide of nitrogen with the formula N20. At room temperature, it is a colourless non-flammable gas, and has a slightly sweet scent and taste. Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain-reducing effects. Its colloquial name, "laughing gas", coined by Humphry Davy, is due to the euphoric effects upon inhaling it, a property that has led to its recreational use as a dissociative anaesthetic