Synonyms to fill in for

act for, advance, answer for, appear for, assist, back up, be instrumental, change places with, commission, crowd out, cut out, deputize, displace, double for, facilitate, forward, front for, ghost, ghostwrite, go between, mediate, minister to, pinch-hit, pinch-hit for, promote, relieve, replace, represent, serve, speak for, spell, spell off, stand in for, subrogate, subserve, substitute for, succeed, supersede, supplant, swap places with, understudy, understudy for, alternate, advocate, agent, alter ego, alternating, alternative, amicus curiae, analogy, attorney, back and fill, back-and-forth, backup, backup man, bandy, battledore and shuttlecock, be here again, be quits with, beating, champion, change, changeling, circle, circling, come again, come and go, come around, come round, come round again, come up again, commute, comparison, compensate, complementary, cooperate, copy, corresponding, counterchange, counterfeit, cover, cycle, cyclic, deputy, dither, do a hitch, do a stint, do a tour, do time, double, dummy, ebb and flow, enlist, epochal, equal, equivalent, equivocate, ersatz, even, eve