also: ヒマシゆ
noun
castor oil
A vegetable oil obtained from castor beans, used as a laxative or industrial lubricant.
ひまし油は昔、下剤としてよく使われた。
Castor oil was often used as a laxative in the past.
From ひまし (castor bean) + 油 (oil). The word ひまし is thought to derive from the plant's scientific name Ricinus, possibly via Portuguese or Dutch, but the exact path is uncertain.