/ Dictionary / Index H hydroxy-: Meaning and Definition of Find definitions for: hydroxy- Pronunciation: [key] a combining form used in the names of chemical compounds in which the hydroxyl group is present: hydroxyketone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hydroxy- (Thesaurus) hydroxide ion hydroxyacetic acid Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language