Why isn't nitrous oxide a nitrogen oxide?

It is. They are a holdover from before IUPAC naming conventions started. -ous indicated lower valency, while -ic indicated higher valency. Eg: Ferrous and ferric oxide. read more

The bulk part, 70-95%, is lost via animal waste.6 This extra nitrogen gets added to the environment and is causing increases in nitrous oxide emissions. Runoff and leaching of fertilizers Runoff and leaching of fertilizers from agricultural soils are an indirect source of nitrous oxide. read more

Recreational use of nitrous oxide is the inhalation of nitrous oxide gas for its euphoriant effects. The gas is sometimes called Whippets, Laughing Gas, the Epiphany Drug, or Hippy Crack. In Australia, nitrous oxide bulbs are known as nangs. read more