ozone

ozone

noun \ˈō-ˌzōn\

Definition of OZONE

: a triatomic very reactive form of oxygen that is a bluish irritating gas of pungent odor, that is formed naturally in the atmosphere by a photochemical reaction and is a major air pollutant in the lower atmosphere but a beneficial component of the upper atmosphere, and that is used for oxidizing, bleaching, disinfecting, and deodorizing

—ozo·nic \ō-ˈzō-nik, -ˈzän-ik\ adjective