Breadcrumb Home > Dictionary > Index C castor-oil plant: Meaning and Definition of Find definitions for: cas'tor-oil' plant" Pronunciation: (kas'tur-oil', kä'stur-), [key] a tall plant, Ricinus communis, of the spurge family, cultivated for its ornamental foliage and having poisonous seeds that are the source of castor oil. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. castor oil castor sugar TrendingHere are the facts and trivia that people are buzzing about. Did Birds Evolve from Dinosaurs? The Twelve Dancing Princesses Current Events This Week: January 2023 African Americans by the Numbers Andersen's Fairy Tales: Contents The Celtic Twilight: A Teller of Tales ✖ Related Content Daily Word Quiz: antiphon Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language