peremptory

offensively self-assured or given to exercising usually unwarranted power; "an autocratic person"; "autocratic behavior"; "a bossy way of ordering others around"; "a rather aggressive and dominating character"; "managed the employees in an aloof magisterial way"; "a swaggering peremptory manner"

not allowing contradiction or refusal; "spoke in peremptory tones"; "peremptory commands"

putting an end to all debate or action; "a peremptory decree"