1. (a.) Containing a command; required; compulsory; as, a mandatory meeting\; preceptive; directory.

2. (n.) Same as Mandatary.

absolute authoritative binding canonical choiceless commanded commanding compelling compulsatory compulsory conclusive de rigueur decisive decretory demanded dictated didactic entailed essential exigent final forced formulary hard and fast hard-and-fast imperative imperious importunate imposed indispensable inevitable instructive involuntary irrevocable mandated must necessary necessitous needed needful obligatory official peremptory preceptive prescribed prescript prescriptive regulation required requisite rubric standard statutory ultimate urgent without appeal without choice