indispensable Antonyms

dispensable subordinate tautologic tertiary trifling trivial unessential unsubstantial useless valueless surplus supplementary substituent succedaneum superaddition superficial superfluous superimposed supernumerary supervenient supplanter worthless unimportant de trop disorganic non-essential unneeded overpayment spare part stoppable unrequested nonmandatory meter maid meaningless irrelevant unnecessary backup procedural fill-in avertable locum pinch hitter less important accessorial disposable elective evitable extrinsic frivolous immaterial