# nitrogen

/ˈnaɪtɹədʒən/ (US) · /nˈaɪtɹədʒən/ (UK)

Source: https://englishreference.com/word/nitrogen
Updated: 2026-06-20

## Senses

### 1. chemical element or gas

noun · CEFR B2

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

For teachers: 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.

### 2. liquid nitrogen

noun · CEFR C1 · Technical

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

For teachers: 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.

Usage: Often used in the compound 'liquid nitrogen'.

## Examples

- Plants need nitrogen in the soil to grow strong and healthy.
- Farmers often add nitrogen to their fields to ensure the crops have enough nutrients for a successful harvest.
- The industrial synthesis of ammonia from atmospheric nitrogen revolutionized global agriculture by providing a reliable source of synthetic fertilizer, though it also introduced significant environmental challenges.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.