Definition of "ozone" []

• An unstable, poisonous allotrope of oxygen, O3, that is formed naturally in the ozone layer from atmospheric oxygen by electric discharge or exposure to ultraviolet radiation, also produced in the lower atmosphere by the photochemical reaction of certain pollutants. It is a highly reactive oxidizing agent used to deodorize air, purify water, and treat industrial wastes. (noun)
• Informal Fresh, pure air. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The term ozone hole or Antarctic ozone hole refers to the seasonal depletion of stratospheric ozone in a large area over Antarctica."
• "According to Messrs Frémy and Becquerel, the term ozone ought to be abandoned; for, after a series of careful experiments, they have come to the conclusion, that there is no real transformation of matter in the production of ozone, but that it is nothing more than 'electrified oxygen,' or oxygen in a particular state of chemical affinity."
• "We were also careful of the sun's rays because the hole in the ozone is above Antarctica; we wore forty-five level sunblock twenty-four hours a day."