English Reference

Word

nitrogen

Phoneticsni·tro·gen

US/ˈnaɪtɹədʒən/

UK/nˈaɪtɹədʒən/

Definitions

01chemical element or gas

B2 · Science

n. a gas that has no colour or smell and makes up about 78% of the Earth's atmosphere.

n. the chemical element with atomic number 7; most commonly encountered as a colorless, odorless diatomic gas (N₂) that is the primary constituent of air.

“Plants need nitrogen in the soil to grow strong and healthy.”

“Nitrogen is essential for life on Earth, as it is a fundamental component of amino acids, proteins, and nucleic acids like DNA.”

Usage

Usually uncountable when referring to the gas or the element in general.

02liquid nitrogen

C1 · Science

n. the very cold liquid form of nitrogen used to freeze things quickly.

n. nitrogen in a liquid state at extremely low temperatures, typically used as a refrigerant or in cryogenics.

“The chef used liquid nitrogen to make instant ice cream for the guests.”

“The laboratory stored the biological samples in tanks of liquid nitrogen to ensure they remained preserved at cryogenic temperatures.”

Technical

Usage

Often used in the compound 'liquid nitrogen'.

Real-World Examples

“London had high levels of the harmful gas nitrogen dioxide which comes from motor vehicles.”
BBC News · 18 Aug 2026
“The researchers examined other possible causes, including rainfall, temperature, grazing, fire, nitrogen pollution and changes in grass species.”
Phys.org · 20 Aug 2026

Etymology

Borrowed from French nitrogène (coined by French chemist and physician Jean-Antoine Chaptal in 1790). By surface analysis, nitro- + -gen. See also niter.

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

Collocations

nitrogen dioxide

This entry

Level
B2 · Upper Intermediate
Frequency
Frequent
Updated

Scan code

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English Reference