/ Thesaurus / X Synonyms of xanthium Find synonyms for: Noun1. Xanthium, genus Xanthium, asterid dicot genususage: coarse herbs having small heads of greenish flowers followed by burrs with hooked bristlesWordNet 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