castor oil

noun

1. a colorless to pale yellow, viscid liquid, usually obtained from the castor bean by a pressing process: used as a lubricant, in the manufacture of certain soaps and creams, and in medicine chiefly as a cathartic.

castor oil

noun

1. a colourless or yellow glutinous oil obtained from the seeds of the castor-oil plant and used as a fine lubricant and as a cathartic

Word History and Origins

Origin of castor oil¹

1740–50; castor (perhaps variant spelling of caster ) + oil; perhaps so called because of its purgative effect