Synonyms to voluntary

advised, aforethought, aimed, aimed at, calculated, conscious, considered, contemplated, deliberate, deliberated, designed, envisaged, envisioned, intended, intentional, knowing, meant, meditated, of design, planned, premeditated, prepense, projected, proposed, purposed, purposeful, purposive, reasoned, studied, studious, teleological, thought-out, weighed, willful, witting, 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, optional, optionality, personnel, phony, pinch, pinch hitter, pleasure, possibility, possible choice, preference, pretext, provisional, proxy, relief, replacement, replacing, representative, reserve, reserves, ringer, saving clause, sec