copacetic (adj.)youdaoicibaDictYouDict[copacetic 词源字典]
1919, but it may have origins in 19c. U.S. Southern black speech. Origin unknown, suspects include Latin, Yiddish (Hebrew kol b'seder), Italian, Louisiana French (coupe-sétique), and Native American. None is considered convincing by linguists.[copacetic etymology, copacetic origin, 英语词源]