/ Dictionary / Index S sodium monoxide: Meaning and Definition of Find definitions for: so'dium monox'ide Pronunciation: [key] — Chem. Chem. a white powder, NaO, that reacts violently with water to produce sodium hydroxide. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sodium methylate sodium nitrate Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language