Synonyms to optional

alternative, additional, agent, alternate, alternate choice, analogy, another, attainable, backup, change, changeling, choice, comparison, contingency, copy, counterfeit, deputy, different, discretion, discretional, disjunctive, double, druthers, dummy, election, elective, equal, equivalent, ersatz, escape clause, escape hatch, exchange, exchangeable, fake, fill-in, ghost, ghostwriter, imitation, interchangeable, locum tenens, loophole, makeshift, metaphor, metonymy, mock, next best thing, option, optionality, personnel, phony, pinch, pinch hitter, pleasure, possibility, possible choice, preference, pretext, provisional, proxy, relief, replacement, replacing, representative, reserve, reserves, ringer, saving clause, second string, secondary, selection, sign, spare, spares, stand-in, stopgap, sub, substituent, substitute, substitution, succedaneum, superseder, supplanter, surrogate, symbol, synecdoche, temporary, tentative, third string, token, understudy, utility, utility player, variant, vicar, vicarious, vice-president, vice-regent, volitional, voluntary, way of escape, way out, will and pleasure,