substitute

Synonyms: acting additional alternate another artificial backup counterfeit dummy ersatz experimental false imitation makeshift mock near other provisional proxy pseudo replacement representative reserve second sham simulated spurious stopgap substitutive supplemental supplementary supposititious surrogate symbolic temporary tentative vicarial vicarious

Synonyms: agent alternate assistant auxiliary backup changeling delegate deputy dernier ressort double dummy equivalent expediency expedient fill-in ghost ghost writer locum locum tenens makeshift pinchhitter procurator proxy recourse refuge relay relief replacement representative reserve resort resource standby stand-in stopgap sub succedaneum successor supplanter supply surrogate symbol temp temporary temporary expedient understudy vicar

Antonyms: permanent

Synonyms: act for alternate answer for back up be in place of change commute cover for deputize displace do the work of double for fill in for fill one’s position go as proxy relieve replace serve in one’s stead spell stand for stand in for sub supersede supplant swap swap places with switch take another’s place take over