/ Dictionary / Index M monoxide: Meaning and Definition of Find definitions for: mon•ox•ide Pronunciation: (mon-ok'sīd, mu-nok'-), [key] — n. Chem. an oxide containing one oxygen atom in each molecule. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: monoxide (Thesaurus) monovision lenses monozygotic Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language