The Oxford Thesaurus An A-Z Dictionary of Synonyms - peremptoryadj.

1) commanding, imperative, compelling, obligatory, mandatory, irrefutable, incontrovertible, decretal: After the sound of marching came a peremptory knock at the door. 2) decisive, final, preclusive, arbitrary, categorical, unequivocal, dogmatic, unconditional, unreserved, flat, out-and-out, outright, unqualified, unmitigated: The juror was subject to peremptory dismissal because he was the defendant's cousin. 3) imperious, authoritative, tyrannical, despotic, dictatorial, autocratic, emphatic, positive, firm, insistent, Colloq bossy: How dare you take such a peremptory tone when speaking to your father!