mandatory Synonyms

required compulsory necessary mandatary obligatory indispensable unavoidable essential vital mandate binding rule-bound regulation pressing prescribed prerequisite peremptory obliged needful needed requisite statutory nonoptional de rigueur mandatorily life-and-death of the essence all important incumbent on urgent unavoided stipulated must enforced dictated demanded crucial critical constraining compulsatory compelling commanding coercive clamant bindingly bounden bound enforceable fascicle ministerial