/ Dictionary / Index S sulfur dioxide: Meaning and Definition of Find definitions for: sul'fur diox'ide Pronunciation: [key] — Chem. Chem. a colorless, nonflammable, water-soluble, suffocating gas, SO, formed when sulfur burns: used chiefly in the manufacture of chemicals such as sulfuric acid, in preserving fruits and vegetables, and in bleaching, disinfecting, and fumigating. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sulfur butterfly sulfur dye Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language