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

Louisiana will be using the controversial nitrogen gas method for its execution, marking the end of a 15-year hiatus on capital punishment in the state. —James Powel, USA TODAY, 13 Feb. 2025

Two death row inmates have execution dates in March after Gov. Landry established protocols for using nitrogen gas. —Chelsea Brasted, Axios, 13 Feb. 2025

Avoid over fertilizing figs, as excess nitrogen will encourage shoot growth at the expense of fruiting. —Kim Toscano, Southern Living, 12 Feb. 2025

Little is understood about nitrogen hypoxia, where an inmate is made to suffocate on nitrogen gas delivered through a face mask, and Alabama was the only U.S. state prior to this week that had released a protocol for this type of execution. —Emily Mae Czachor, CBS News, 11 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