/ Dictionary / Index S sulfinyl group: Meaning and Definition of Find definitions for: sul'finyl group" Pronunciation: [key] — Chem. Chem. the bivalent group >SO. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sulfinyl sulfisoxazole Related Content Daily Word Quiz: meddlesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language