(1):
(n.) A process of oxidation, in which nitrogenous vegetable and animal matter in the presence of air, moisture, and some basic substances, as lime or alkali carbonate, is converted into nitrates.
(2):
(n.) The act or process of oxidizing nitrogen or its compounds so as to form nitrous or nitric acid.
(3):
(n.) The act, process, or result of combining with nitrogen or some of its compounds.