/ Thesaurus / S Synonyms of superoxide anion Find synonyms for: Noun1. superoxide, superoxide anion, anionusage: the univalent anion O2-; "much of the O2 supporting cellular respiration is reduced to the superoxide anion O2-"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language