English Reference

Word

ozone

US/ˈoʊˌzoʊn/

UK/ˈəʊzəʊn/

Definitions

01atmospheric gas

B2 · Science

n. a form of oxygen that forms a layer high in the sky, protecting the Earth from the sun's dangerous rays.

n. an allotrope of oxygen (O₃) found in the stratosphere that absorbs most of the sun's ultraviolet radiation.

“Scientists are worried about the hole in the ozone layer over the Antarctic.”

“The Montreal Protocol was designed to protect the ozone layer by phasing out the production of substances responsible for its depletion.”

Technical

Usage

Usually used as an uncountable noun; frequently appears in the compound 'ozone layer'.

02fresh seaside air

C1

n. fresh, clean air, especially the kind you breathe when you are at the beach.

n. fresh, bracing air, particularly that found at the seaside and associated with the smell of the ocean.

“We went for a walk along the cliffs to breathe in some of that healthy ozone.”

“After a week in the smoggy city, the crisp seaside ozone was a welcome relief for the travellers.”

British English · Informal

Teaching tip

This sense is based on a historical misconception that the smell of the sea was ozone; it is now used figuratively to mean 'bracing air'.

Synonyms

fresh airsea breeze

Antonyms

03to treat with gas

C2 · Science

v. to clean or treat something using ozone gas.

v. to subject to the action of ozone, typically for the purpose of purification or bleaching.

“The company uses a special machine to ozone the water and kill bacteria.”

“The facility began to ozone the wastewater as a final stage of treatment to ensure all organic contaminants were neutralised.”

Technical

Usage

A transitive verb requiring a direct object.

Synonyms

Real-World Examples

“Ozone has always been an issue in Connecticut because smog blows northeast from New York City.”
Smithsonian Magazine · 18 Sept 2026
“These results suggest that vehicle exhaust and other pollutants are the main sources of ground-level ozone in the region.”
Phys.org · 11 Sept 2026

Etymology

From German Ozon, coined 1840 by Christian Friedrich Schönbein, from Ancient Greek ὄζον (ózon), neuter participle of ὄζω (ózō, “I smell”), in reference to its pungent odour. The “fresh air” sense is from an erroneous former belief that seaweed contains and releases ozone.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Collocations

ozone layer

This entry

Level
B2 · Upper Intermediate
Frequency
Frequent
Updated

Scan code

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English Reference