Ozone (noun)

1. A triatomic molecule, consisting of three oxygen atoms, that occurs in the upper atmosphere and acts as a protective layer against harmful ultraviolet radiation from the sun.
2. A gas with a strong, pungent smell, used in small amounts as a disinfectant and deodorant.

Origin:

Late 19th century: from greek ozōn, neuter present participle of ozō "smell", from ozein "smell".

Examples:

1. The depletion of the ozone layer is a major environmental concern.
2. The ozone layer in the atmosphere protects life on Earth from harmful ultraviolet radiation.
3. The ozone generator was used to purify the air.
4. The ozone layer is found in the stratosphere.
5. The ozone smell is often associated with thunderstorms.