/ Thesaurus / O Synonyms of oxygen mask Find synonyms for: Noun1. oxygen mask, breathing device, breathing apparatus, breathing machine, ventilatorusage: a breathing device that is placed over the mouth and nose; supplies oxygen from an attached storage tankWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language