From Longman Dictionary of Contemporary EnglishRelated topics: Elementsnitrogenni‧tro‧gen /ˈnaɪtrədʒən/●くろまる●くろまる○しろまる noun [uncountable]HCEHEa gas that has no colour or smell, and that forms most of the Earth’s air. It is a chemicalelement: symbolNExamples from the Corpusnitrogen• Globalwarmingoccurs when carbondioxide and some other gases, such as methane and nitrogenoxides, accumulate in the atmosphere.• But close examination showed that speciesintolerant of acid conditions or high nitrogen levels were not reappearing.• Both countries would also limitnitrogen oxide emissions through stricter controls on motorvehicles.• The very low abundances of volatiles and especially the low nitrogen abundance all pose special problems.• Peas and beans put nitrogen into the soil.• Large explosions heat vast masses of the atmosphere to such high temperatures that nitrogen is partially burned to make toxic nitrogen oxides.• On reflection, I think we made the nitrogenbands rather too wide.• Aerozine 50 was used as the fuel, with nitrogen tetroxide as the oxidizer.Originnitrogen(1700-1800)Frenchnitrogène, from nitre (NITIC ACID) + -gène"producing"