substitute

acting alternate backup counterfeit dummy ersatz imitation makeshift mock near proxy pseudo replacement representative reserve second sham simulated stopgap surrogate temporary

additional another artificial experimental false other provisional spurious substitutive supplemental supplementary supposititious symbolic tentative vicarial vicarious

finished genuine permanent real true

backup replacement stand-in surrogate

agent alternate assistant auxiliary changeling delegate deputy double dummy equivalent expediency expedient fill in ghost locum makeshift procurator proxy recourse refuge relay relief representative reserve resort resource standby stopgap sub succedaneum successor supplanter supply symbol temp temporary understudy vicar

dernier ressort ghost writer locum tenens pinch-hitter temporary expedient

being entity permanent

replace supplant swap

alternate change commute deputize displace proxy relieve spell sub supersede switch

act for answer for back up be in place of cover for do the work of double for fill in for fill one's position go as serve in one's stead stand for stand in (for) swap places with take another's place take over

continue keep