/ Dictionary / Index S sulfonic: Meaning and Definition of Find definitions for: sul•fon•ic Pronunciation: (sul-fon'ik), [key] — adj. Chem. sulfo. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sulfone sulfonic acid Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language