- oxygen
- gaseous chemical element, 1790, from Fr. oxygène, coined in 1777 by Fr. chemist Antoine-Laurent Lavoisier (1743-1794), from Gk. oxys "sharp, acid" (see acrid) + Fr. -gène "something that produces" (from Gk. -genes "formation, creation;" see genus). Intended to mean "acidifying (principle)," from Fr. principe acidifiant. So called because oxygen was considered essential in the formation of acids. The element was isolated by Priestley (1774), who thought it an altered form of common air and called it dephlogisticated air.