nitro-

c. 1400, "native sodium carbonate" (a sense now obsolete), from Old French nitre (13c.), from Latin nitrum, from Greek nitron, which is possibly of Eastern origin (compare Hebrew nether "carbonate of soda;" Egyptian ntr). Originally a word for native soda, but also associated since the Middle Ages with saltpeter (potassium nitrate) for obscure reasons; this became the predominant sense by late 16c.

colorless, odorless gaseous element, 1794, from French nitrogène, coined 1790 by French chemist Jean Antoine Chaptal (1756-1832), from Greek nitron "sodium carbonate" (see nitro-) + French gène "producing," from Greek -gen "giving birth to" (see -gen). The gas was identified in part by analysis of nitre. An earlier name for it was mephitic air (1772), and Lavoisier called it azote (see azo-). It forms about 78% of the weight of the Earth's atmosphere. Related: Nitrogenic; nitrogenous.

also nitroglycerin, violently explosive oily light-yellow liquid, 1857, from nitro- + glycerin. So called either because it was obtained by treating glycerine with nitric and sulfuric acids or because it is essentially a nitrate (glyceryl trinitrate). The essential element of dynamite; it is a violent poison when ingested, but in minute doses it is used in the treatment of angina and heart failure.