(imp. & p. p.) of Require.

absolute binding called for compulsatory compulsory conclusive de rigueur decisive decretory dictated entailed essential final hard-and-fast imperative imperious imposed indicated indispensable inevitable involuntary irreducible irreductible irreplaceable irrevocable mandated mandatory must necessary needed needful obligatory peremptory prerequisite prescript prescriptive requisite ultimate unforgoable vital wanted without appeal