/ Dictionary / Index D diol: Meaning and Definition of Find definitions for: di•ol Pronunciation: (dī'ôl, -ol), [key] — n. Chem. glycol (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diol (Thesaurus) Diogenes diolefin Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language