1
: a triatomic very reactive form of oxygen that is a bluish irritating gas of pungent odor, that 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
2
: pure and refreshing air
relished the ozone of morning
ozonic adjective

Examples of ozone in a Sentence

Scientists are concerned about ozone depletion. A light breeze filled the rooms of our seaside cottage with ozone.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Additionally, rising temperatures can worsen ground-level ozone pollution, which presents additional health risks. Joe Edwards, MSNBC Newsweek, 11 July 2025 The federal limit for smog — or ozone pollution near the ground — is 0.070 parts per million. Quinn Clark, jsonline.com, 7 July 2025 Air monitoring sites are color-coded based on the pollutant (ozone or particulate matter) with the highest value. Tanya Wildt, Freep.com, 5 July 2025 On Friday, July 4, and Saturday, July 5, the AQI will reach levels up to 110, meaning ozone or other major air pollutants are expected to reach levels considered unhealthy for sensitive groups. Hailey Roden, The Enquirer, 4 July 2025 See All Example Sentences for ozone

Word History

Etymology

German Ozon, from Greek ozōn, present participle of ozein to smell — more at odor

First Known Use

1840, in the meaning defined at sense 1

Time Traveler
The first known use of ozone was in 1840

Browse Nearby Words

Cite this Entry

“Ozone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ozone. Accessed 20 Jul. 2025.

Kids Definition

ozone

noun
1
: a form of oxygen that is a bluish irritating sharp-smelling gas containing three atoms per molecule, and that is used especially in disinfecting, deodorizing, and bleaching
2
: pure and refreshing air

Medical Definition

ozone

noun
: 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
ozonic adjective

More from Merriam-Webster on ozone

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