kosher (adj.)youdaoicibaDictYouDict[kosher 词源字典]
"ritually fit or pure" (especially of food), 1851, from Yiddish kosher, from Hebrew kasher "fit, proper, lawful," from base of kasher "was suitable, proper." Generalized sense of "correct, legitimate" is from 1896.[kosher etymology, kosher origin, 英语词源]