castor oil

• POS: Noun Phrase
• HYPHEN: cas=tor oil

CIDE DICTIONARY

castor oil,  

 A mild cathartic oil, expressed or extracted from the seeds of the Ricinus communis, or Palma Christi. When fresh the oil is inodorous and insipid.  [1913 Webster]

Castor-oil plant. Same as Palma Christi.

OXFORD DICTIONARY

castor oil, n.
1 an oil from the seeds of a plant, Ricinus communis, used as a purgative and lubricant.
2 (in full castor oil plant) this plant.

Idiom

castor oil bean (or castor bean) a seed of the castor oil plant.

Etymology

18th c.: orig. uncert.: perh. so called as having succeeded CASTOR(2) in the medical sense