joyous (adj.)youdaoicibaDictYouDict[joyous 词源字典]
c. 1300, from Anglo-French joyous, Old French joios "happy, cheerful, merry, glad" (12c., Modern French joyeux), from joie (see joy). Related: Joyously; joyousness.[joyous etymology, joyous origin, 英语词源]