cheval de frise (n.)youdaoicibaDictYouDict[cheval de frise 词源字典]
1680s, from French, literally "horse of Frisia," supposedly because it was first employed there as a defense against cavalry; from French cheval "horse" (see cavalier (n.)). Plural chevaux de frise.[cheval de frise etymology, cheval de frise origin, 英语词源]