ozone

plural ozones

1. uncountableusuallychemistryAn allotrope of oxygen (symbol O₃) having three atoms in the molecule instead of the usual two; it is a toxic gas, generated from oxygen by electrical discharge.

   Lightning flashed again, the thunder came a second later. It rained harder. The smell of ozone was strong. You could feel the charge in the air.

   2018, Nnedi Okorafor, Who Fears Death, HarperVoyager, page 334

   1 more example

   Martin said that the National Park Service invested in “a state-of-the-art ozone nanobubbler filtration system” that is intended to keep algae out.

   2026 June 10, Kit Maher, “‘Residual algae’ coats part of newly opened Reflecting Pool”, in CNN, archived from the original on 11 Jun 2026

2. UKinformaluncountableusuallyFresh air, especially that breathed at the seaside and smelling of seaweed.

   It's got the lot: fresh sea air, ozone, seaweed. You could cut the air with a knife.

   2007, Robert Douglas, Tales of the Unexpected: Somewhere to Lay My Head, unnumbered page

   2 more examples

   A patent obtained in England, and specified far from clearly, for obtaining ozone by boiling seaweed,†† may be mentioned as a curiosity, and also the credulity with which ozone-baths, prepared in this manner, find a ready sale, in spite of, or perhaps rather on account of, their high price.

   1875, William Crookes, The Chemical News, page 99

   To Ramsgate baths she sped, in quest / Of seaweed and ozone ; / For seaweed and ozone were best, / They said, to give her tone.

   1888, L. T. Meade, A. Balfour Symington, Edwin Oliver, Atalanta, volume 1, page 674

present singular third person ozones · participle present ozoning · participle past ozoned · past ozoned

1. transitiveTo treat with ozone.

   I worked nonstop to make the house safe. Periodically I ozoned the first-floor bathroom, but it still made us sick.

   1997, Robert Sampson, Patricia Hughes, Breaking Out of Environmental Illness

   1 more example

   Whenever it exists, as it usually does, even where the tide water freshens at the ebb, it seems to have a purifying tendency, probably by ozoning the superincumbent atmosphere.

   1868, Medical and Surgical Reporter, volume 19, page 392