還元 （カンゲン） restoration, return, reduction, resolution, deoxidization, deoxidation

環境 （カンキョウ） environment, surroundings, circumstances

奪還 （ダッカン） recapture, retaking, recovery, taking back

送還 （ソウカン） sending home, repatriation, deportation

帰る （かえる） to return, to come home, to go home, to go back, to leave (of a guest, customer, etc.), to get home, to get to home plate