[smog] n [smoke + fog] (1905): a fog made heavier and darker by smoke and chemical fumes; also: a photochemical haze caused by the action of solar ultraviolet radiation on atmosphere polluted with hydrocarbons and oxides of nitrogen from automobile exhaust -- smog.less adj
SMOG
Meaning of SMOG in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012