/
pəˈrɛm(p)t(ə)ri, 
ˈpɛrɪm-/
adj.
  - insisting on immediate attention or obedience; brusque and imperious.
 - Law  not open to appeal or challenge; final.
 
Derivative
- peremptorily adv.
  - peremptoriness n.
 
Etymology
ME: via Anglo-Norman Fr. from L. peremptorius ‘deadly, decisive’, from perempt-, perimere ‘destroy, cut off’.