/ Dictionary / Index N nitrous acid: Meaning and Definition of Find definitions for: ni'trous ac'id Pronunciation: [key] — Chem. Chem. an acid, HNO, known only in solution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. nitrous nitrous bacteria Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language