/ Thesaurus / R Synonyms of robitussin Find synonyms for: Noun1. Robitussin, expectorant, expectoratorusage: trade name of an expectorant that loosens phlegm and makes it easier to cough upWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language