Ozone
WordNet
noun
(1) A colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)
WiktionaryText
Noun
- An allotrope of oxygen (symbol O3) having three atoms in the molecule instead of the usual two; it is a blue gas, generated from oxygen by electrical discharge; it is poisonous and highly reactive, but in the upper atmosphere it protects life on Earth from ultraviolet radiation.
- (informally but erroneously) Fresh air, especially that breathed at the seaside and smelling of seaweed.