/ Thesaurus / R Synonyms of ricinus Find synonyms for: Noun1. Ricinus, genus Ricinus, rosid dicot genususage: a genus of herb having only one known species: castor-oil plantWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: grimace Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language