Definitions of peremptory:

• adjective:   putting an end to all debate or action

  Example: "A peremptory decree"

• adjective:   not allowing contradiction or refusal

  Example: "Spoke in peremptory tones"

• adjective:   offensively self-assured or given to exercising usually unwarranted power

  Example: "A swaggering peremptory manner"