Also especially before a vowel, nitr-.

Origin of nitro-

combining form of Greek nítron. See niter Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for nitro-


before a vowel nitr-

combining form
  1. indicating that a chemical compound contains a nitro group, -NO 2nitrobenzene
  2. indicating that a chemical compound is a nitrate esternitrocellulose

Word Origin for nitro-

from Greek nitron natron
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 nitro-

before vowels nitr-, word-forming element used scientifically and indicating "nitrogen, nitrate" or "nitric acid," from comb. form of Greek nitron (see nitre).

Online Etymology Dictionary, © 2010 Douglas Harper

nitro- in Medicine


  1. Nitrate; nitrogen:nitrogenase.
  2. Containing the univalent radical NO2:nitrous.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.