castor oil

American  

noun

• castor oils
  plural

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.

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castor oil British  

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

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Other Word Forms

Noun Inflected Forms

• castor oils
  plural

Etymology

Origin of castor oil

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

Example Sentences

See Examples For:

castor oil

India mainly exports rice, shrimp, honey, vegetable extracts, castor oil and black pepper, while the US sends almonds, walnuts, pistachios, apples and lentils.

From BBC ● Mar. 30, 2025

The modified Arabidopsis overcame metabolic bottlenecks and produced significant amounts of an oil similar to castor oil that it doesn't naturally produce.

From Science Daily ● Apr. 30, 2024

Newer products include a hair strengthening collection with biotin and Jamaican castor oil, and a wig care collection that uses apple cider vinegar to remove build-up from weaves and wigs.

From Los Angeles Times ● Nov. 2, 2023

This is, in some sense, castor oil to swallow.

From Washington Post ● Feb. 28, 2023

My stomach hurt as if my mother had dosed me with castor oil.

From "The Lions of Little Rock" by Kristin Levine