occupant (n.)youdaoicibaDictYouDict[occupant 词源字典]
1590s, "one who takes possession of something having no owner," from Middle French occupant (15c.) or directly from Latin occupantem (nominative occupans), present participle of occupare "to take possession of" (see occupy). Earlier noun form was ocupier (early 14c.).[occupant etymology, occupant origin, 英语词源]