nitrogen

noun

ni·​tro·​gen ˈnī-trə-jən 

: a nonmetallic chemical element with atomic number 7 that under standard conditions is a colorless, odorless, inert gas, that constitutes 78 percent of the Earth's atmosphere, and that is used especially in the industrial synthesis of ammonia, as a component of inert atmospheres, and in liquid form as a refrigerant

—often used before another noun

the nitrogen cycle

nitrogen fertilizer

see Chemical Elements Table

Examples of nitrogen in a Sentence

Recent Examples on the Web

Using precious metals and chemical reactions, catalytic converters transform harmful carbon monoxide, hydrocarbons and nitrogen oxides into significantly less harmful carbon dioxide, nitrogen and water vapor. — Peter Lyon, Forbes.com, 22 July 2026

And so unequivocally nitrogen fertilizers, on which the farm sector spends most of its money, became significantly more expensive. — David Frum, The Atlantic, 22 July 2026

While used coffee grounds contain a little nitrogen, an element that plants need to grow, the nitrogen isn’t in a form that’s easy for plants to use. — Leanne Potts, Better Homes & Gardens, 22 July 2026

Known as nitrogen-vacancy centers, these atomic-scale structures allow the system to manipulate electron and nuclear spins without needing liquid helium or high-vacuum environments. — Mrigakshi Dixit, Interesting Engineering, 21 July 2026

Word History

Etymology

French nitrogène, from nitre niter + -gène -gen

First Known Use

1791, in the meaning defined above

Phrases Containing nitrogen

• nitrogen balance
• nitrogen cycle
• nitrogen dioxide
• nitrogen fixation
• nitrogen-fixer
• nitrogen-fixing
• nitrogen mustard
• nitrogen narcosis
• nitrogen oxide
• nitrogen tetroxide

Kids Definition

nitrogen

noun

ni·​tro·​gen ˈnī-trə-jən 

: a colorless tasteless odorless element that occurs as a gas which makes up 78 percent of the atmosphere and that forms a part of all living tissues see element

nitrogenous

nī-ˈträj-ə-nəs 

adjective

Medical Definition

nitrogen

noun

ni·​tro·​gen ˈnī-trə-jən 

: a common nonmetallic element that in the free form is normally a colorless odorless tasteless insoluble inert diatomic gas comprising 78 percent of the atmosphere by volume and that in the combined form is a constituent of biologically important compounds (as proteins, nucleic acids, and alkaloids) and hence of all living cells as well as of industrially important substances (as cyanides, fertilizers, dyes, and antibiotics)

—symbol N see Chemical Elements Table