Peremptory means final and absolute, without needing any underlying justification. For example, English law, in the Arbitration Act section 41(5), allows tribunals to summarily issue “peremptory orders,” without elaboration, to compel non-complying parties to comply with a binding arbitration result. See also peremptory challenge.
[Last updated in December of 2020 by the Wex Definitions Team]