cas·tor oil
noun/ˈkɑːstər ɔɪl/
/ˈkæstər ɔɪl/
[uncountable]- a thick yellow oil obtained from a tropical plant and used in the past as a type of medicine, usually as a laxative
蓖麻油 Word Originmid 18th cent.: perhaps so named because it succeeded castor (an oily reddish brown substance) in medicinal use.