nitrogen oxide

English Thesaurus

1. any of several oxides of nitrogen formed by the action of nitric acid on oxidizable materials; present in car exhausts (noun.substance)

hypernym	:	pollutant,
definition	:	waste matter that contaminates the water or air or soil (noun.substance)

hypernym	:	oxide,
definition	:	any compound of oxygen with another element or a radical (noun.substance)