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

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.
Now imagine that on Tuesday, the nitrogen dioxide held at 105, while ozone levels dropped to 30. Daniel Engber, The Atlantic, 24 July 2026 Air quality Unhealthful air quality is expected for inland valleys, the South Coast Air Quality Management District, which issued an ozone advisory for Thursday. Alex Wigglesworth, Los Angeles Times, 23 July 2026 Large plumes of smoke can encourage chemical reactions that alter ground-level ozone quality. Hali Smith, Idaho Statesman, 22 July 2026 But the air quality was expected to worsen on July 20 from residual smoke, according to AirNow, with the possibility that ozone levels could also reach close to Code Orange levels as the city sees sunny skies and temperatures in the mid-80s. Finch Walker, USA Today, 20 July 2026 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 30 Jul. 2026.

Kids Definition

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

: 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

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