nitrogen n.

before vowels nitr-, word-forming element used scientifically and indicating nitrogen, nitrate, or nitric acid; from Greek nitron (see nitre).

word-forming element technically meaning "something produced," but mainly, in modern use, "thing that produces or causes," from French -gène (18c.), from Greek -genes "born of, produced by," which is from the same source as genos "birth," genea "race, family," from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups. First used in late 18th century French chemistry (see oxygen), it probably involves a misunderstanding of -genes, as though it meant "that which produces."

before vowels az-, word-forming element denoting the presence of nitrogen, used from late 19c. as combining form of azote (1791), the old term for "nitrogen," from Greek a- "not, without" (see a- (3)) + zoion "a living being" (from PIE root *gwei- "to live"). Azote was coined in French by Lavoisier & de Morveau because living things cannot survive in the pure gas.