/ Thesaurus / R Synonyms of respiratory system Find synonyms for: Noun1. respiratory system, systema respiratorium, systemusage: the system for taking in oxygen and giving off carbon dioxide; in terrestrial animals this is accomplished by breathingWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language