(chemistry, biochemistry) the conversion of atmospheric nitrogen into ammonia and organic derivatives, by natural means, especially such conversion, by microorganisms in the soil, into a form that can be assimilated by plants

The natural circulation of nitrogen, in which atmospheric nitrogen is converted to nitrogen oxides by lightning and deposited in the soil by rain, where it is assimilated by plants and either eaten by animals (and returned as faeces) or decomposed back to elemental nitrogen by bacteria.

Of a plant, microbe, etc., able to convert inorganic nitrogen into a form usable in the biosphere.

(chemistry) The rapid inversion of the lone pair in a molecule such as a tertiary amine which prevents it from being chiral.

(inorganic chemistry) The binary compound NO₂, a brownish gas that is a poisonous air pollutant; it exists in equilibrium with dinitrogen tetroxide.

(chemistry) The binary compound of nitrogen and iodine, NI₃; a dark red explosive solid.

(chemistry) the binary compound of nitrogen and bromine, NBr₃; a dark red explosive liquid

Nitrogen that has been cooled to the liquid state; used in cryogenics.

(chemistry) Synonym of dinitrogen tetroxide

(chemistry) The binary compound of nitrogen and fluorine, NF₃; a corrosive gas.