“Peremptory” — Calling for a conclusive end to an action; not open to delay. A peremptory order must be performed by the given time, with no further extensions.
In non-legal usage, peremptory can refer to someone who is offensively self-assured, given to exercising usually unwarranted power, dictatorial and brusque.
Note that this word can be confused with preemptory — an action made in anticipation of an event.
Colvin v. Gillies Hillcrest Variety, 2004 HRTO 3 (CanLII)
Toronto Licensing Tribunal Hearing – Mistre Tegegn Gebre Kidan
Matthew Roland Riddell v. Law Society of Upper Canada 2009 ONLSHP 45 (CanLII)