hegira (n.)youdaoicibaDictYouDict[hegira 词源字典]
1580s, the flight of Muhammad from Mecca to Medina (July 16, 622 C.E.), the event from which the Islamic calendar reckons, from Medieval Latin hegira, from Arabic hijrah "departure," from hajara "to depart."[hegira etymology, hegira origin, 英语词源]