[ nahy-truh s ]
/ ˈnaɪ trəs /

adjective Chemistry.

pertaining to compounds obtained from niter, usually containing less oxygen than the corresponding nitric compounds.
containing nitrogen, usually in the trivalent state.

Nearby words

  1. nitrosourea,
  2. nitrostarch,
  3. nitrosyl,
  4. nitrosylsulfuric,
  5. nitrosylsulfuric acid,
  6. nitrous acid,
  7. nitrous bacteria,
  8. nitrous ether,
  9. nitrous oxide,
  10. nitroxanthic acid

Origin of nitrous

First recorded in 1595–1605, nitrous is from the Latin word nitrōsus full of natron. See nitroso-

Related formsnon·ni·trous, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for nitrous

British Dictionary definitions for nitrous


/ (ˈnaɪtrəs) /


of, derived from, or containing nitrogen, esp in a low valency state

Word Origin for nitrous

C17: from Latin nitrōsus full of natron see nitre

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for nitrous



c.1600, from Latin nitrosus, from nitrum (see nitre). Originally "of nitre, pertaining to nitre;" more precise use in chemistry (designating a compound in which the nitrogen has a lower valence than the corresponding nitric compound) is from 1780s. Nitrous oxide attested from 1800.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for nitrous


[ nītrəs ]


Of, derived from, or containing nitrogen, especially in a valence state lower than that in a comparable nitric compound.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for nitrous


[ nītrəs ]

Containing nitrogen, especially nitrogen with a valence of 3. Compare nitric.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.