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

Frazier and his attorneys unsuccessfully argued that the use of nitrogen gas violated Frazier's Eighth Amendment protections against cruel and unusual punishment. —James Powel, USA TODAY, 2 Mar. 2025

The pollutants travel down a duct into the floating processing unit, which converts them into clean nitrogen and water. —Katie Fehrenbacher, Axios, 26 Feb. 2025

The country's first execution using nitrogen gas was carried out last year in Alabama, which has now executed four people using the method. —CBS News, 24 Feb. 2025

Kenneth Eugene Smith, 58, was strapped to a gurney and pronounced dead 15 minutes after breathing in nitrogen gas through a mask, depriving him of oxygen, said prison officials at the William C. Holman Correctional Facility in Atmore. —Erik Ortiz, NBC News, 21 Feb. 2025

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