horse-chestnut (n.)youdaoicibaDictYouDict[horse-chestnut 词源字典]
1590s, from horse + chestnut. A tree probably native to Asia, introduced in England c. 1550; the name also was extended to similar North American species such as the buckeye. Said to have been so called because it was food for horses. The nut resembles that of the edible chestnut but is bitter to the taste.[horse-chestnut etymology, horse-chestnut origin, 英语词源]