Definition of ozone in US English:



  • 1A colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light. It differs from normal oxygen (O₂) in having three atoms in its molecule (O₃).

    • ‘The four usual agents of deterioration in the air apart from oxygen and water are sulphur dioxide, hydrogen sulphide, ozone and nitrogen dioxide.’
    • ‘Automotive emissions are a major source of ozone and carbon monoxide pollution.’
    • ‘The mean temperature of the earth's surface is about 33°C warmer than it would be in the absence of natural greenhouse gases such as water vapour, carbon dioxide, methane, nitrous oxide, and ozone.’
    • ‘Although CO2 is by far the most well known green house gas, we humans also produce others in the form of methane, CFC's, ozone and nitrous oxide.’
    • ‘Recent experiments have begun identifying oxidizing gases, such as ozone and molecules containing the halogens bromine and chlorine, as triggers for that mercury fallout.’
    • ‘The District's urban forest improves air quality by removing nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone, and particulate matter.’
    • ‘For example, plant tissues challenged with acutely toxic levels of ozone rapidly produce a burst of ethylene.’
    • ‘Adding that third oxygen atom makes ozone a very pushy and highly obnoxious little molecule.’
    • ‘Even though it's made of only three little molecules of oxygen, ozone can be a pretty big topic.’
    • ‘Water vapour, carbon dioxide, ozone, methane, nitrous oxide, and the chlorofluorocarbons are known as Greenhouse Gases.’
    • ‘Your lungs may be exposed to pollutants such as ozone, carbon monoxide, sulfur dioxide, and sulfuric acid.’
    • ‘Public water systems treat water with chlorine, ultraviolet light or ozone to kill E. coli.’
    • ‘The sunlight splits the chlorine into highly reactive ions that break ozone down into normal oxygen molecules.’
    • ‘Nitrogen Oxides, primarily from automobile exhaust, ramp up ozone production to toxic levels.’
    • ‘Already used to control bacteria in some pools and aquariums, ozone gas causes oxidizing reactions that damage tissue.’
    • ‘Carbon monoxide is not only a hazardous air pollutant itself, it is also a chemical compound that produces ozone, a greenhouse gas that is a human health hazard.’
    • ‘Biofuels, such as ethanol, can reduce carbon dioxide, ozone formation and carbon monoxide by as much as 90 percent.’
    • ‘Photo chemical smog is caused by the chemical interacting with the sunlight creating ozone and other toxic substances.’
    • ‘A form of oxygen, ozone protects life on Earth from the harmful effects of ultraviolet radiation.’
    • ‘The city is constantly bathed in a visible haze of harmful pollutants: Sulphur dioxide, nitrogen oxides, ozone and smoke.’
    1. 1.1
      short for ozone layer
      • ‘The Institute Nacional de Meteorologia provided the radiometric, columnar ozone and meteorological information for the three stations used in this study.’
      • ‘This story is too far fetched, because a hole in the ozone in Antartica would generate so much heat, that Antartica would be a tropical forest, or a fiery wasteland!’
      • ‘Tropospheric ozone can permanently damage people's lungs and prohibit plants from producing and storing food.’
      • ‘Research published in 1994 suggests that increased ultraviolet radiation caused by stratospheric ozone depletion may be killing frog eggs.’
      • ‘Recent changes in surface UV solar radiation and stratospheric ozone have also been reported at a high Arctic site, although it is still too early to make trend estimates.’
      • ‘In the upper atmosphere, or the stratosphere, ozone is very good, as it acts as a shield to protect life on Earth from harmful Ultraviolet sunlight.’
      • ‘Between 1980 and 2000, the protective ozone in the stratosphere, about 10 to 30 miles high, decreased 3 percent.’
      • ‘Standard vertical profiles of pressure, temperature, relative humidity and ozone density are selected, according to the U.S. Standard Atmosphere.’
      • ‘The ozone hole still contains ozone, just at extremely low levels compared with the surrounding stratosphere.’
      • ‘High in the atmosphere this is not a problem as ozone blocks the harmful rays from the sun.’
      • ‘Also, the presence of stratospheric ozone sandwiched between the satellite and the troposphere makes seeing tropospheric ozone very difficult.’
      • ‘Acid rain, stratospheric ozone depletion, and climate change are major regional or global problems arising from atmospheric pollution.’
      • ‘The stratosphere is rich in ozone, a greenhouse gas that filters out dangerous solar particles such as ultraviolet light.’
      • ‘‘No one predicted the dramatic loss of ozone in the upper stratosphere of the northern hemisphere in the spring of 2004,’ she said.’
      • ‘The exhaust gases that these cars produce are very harmful to the environment, causing a variety of ecological problems such as ozone depletion and global warming.’
      • ‘The Sun is a strong UV emitter but only near UV reaches the surface of the Earth because the ozone in the atmosphere absorbs all wavelengths below 290 nm.’
      • ‘So, as we learn more about stratospheric ozone and climate change, what were once two separate problems have become more and more entwined.’
      • ‘Researchers analyzed data from several sources, and found a strong correlation between cosmic ray intensity and ozone depletion.’
      • ‘No one disputes that stratospheric ozone recovery is one of the environmental movement's great success stories.’
      • ‘Part I of The Ozone Layer relates the history of our understanding of stratospheric ozone.’
    2. 1.2informal Fresh invigorating air, especially that blowing onto the shore from the sea.
      • ‘Because of wind patterns, most ozone blows east to Fountain Hills.’
      • ‘The rain had taken the city's baseline odor of fear and body fluids and replaced it with fresh, sweet-smelling ozone.’


Mid 19th century: from German Ozon, from Greek ozein ‘to smell’.