emigration (n.)youdaoicibaDictYouDict[emigration 词源字典]
1640s, from Late Latin emigrationem (nominative emigratio) "removal from a place," noun of action from past participle stem of Latin emigrare "move away, depart from a place," from assimilated form of ex- "out" (see ex-) + migrare "to move" (see migration).[emigration etymology, emigration origin, 英语词源]