/ Thesaurus / B Synonyms of bog rhubarb Find synonyms for: Noun1. butterbur, bog rhubarb, Petasites hybridus, Petasites vulgaris, herb, herbaceous plantusage: small Eurasian herb having broad leaves and lilac-pink rayless flowers; found in moist areasWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language