/ Dictionary / Index S superoxide: Meaning and Definition of Find definitions for: su•per•ox•ide Pronunciation: (s"pur-ok'sīd, -sid), [key] — n. Chem. a compound containing the univalent ion O. peroxide (def. 1a, b). Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: superoxide (Thesaurus) superovulate superparasite Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language