/ Dictionary / Index H hydroxide ion: Meaning and Definition of Find definitions for: hydrox'ide i"on Pronunciation: [key] the anion OH−. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hydroxide hydroxy- 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