noun

• (inorganic chemistry) An 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."
• (British, informal) Fresh air, especially that breathed at the seaside and smelling of seaweed.
  "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."

verb

• (transitive) To treat with ozone.
  "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."