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

Freeing up atoms from nitrogen gas requires severing powerful molecular bonds and takes an enormous amount of energy, according to Williams, who was not involved in the research. —Mindy Weisberger, CNN Money, 28 Mar. 2025

In four of those states – Alabama, Louisiana, Mississippi and Oklahoma – nitrogen gas is specifically named as the deadly chemical agent used in such executions. —Peter D'abrosca, FOXNews.com, 26 Mar. 2025

And last year, Alabama became the first state in the nation to carry out an execution with nitrogen gas. —Romy Ellenbogen, Miami Herald, 26 Mar. 2025

Arizona executed a man by an injection Wednesday and Louisiana used nitrogen gas for the first time Tuesday, putting a man to death as that state ended a 15-year pause on executions. —Curt Anderson, Orlando Sentinel, 20 Mar. 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