/ Dictionary / Index D dithionic acid: Meaning and Definition of Find definitions for: di'thion'ic ac'id Pronunciation: [key] — Chem. Chem. a strong, unstable acid, HSO, known only in solution and in the form of its salts. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. dithionic dithyramb Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language