Imperious
Etymology
From Latin imperiosus, "commanding, mighty," from imperium, "command, authority, empire" — the same root behind "emperor" and "imperial." Imperium was the formal power to give orders that Roman magistrates and generals held. Applied to a person’s manner, it names the bearing of someone who behaves as though vested with exactly that unquestionable authority.
adjective · /im-PEER-ee-us/
Domineering and arrogant, expecting to be obeyed without question.
What it names
The manner of a person who issues wishes as commands and assumes the world exists to carry them out.
Example
With an imperious wave, she dismissed the waiter before he could finish describing the specials.
Related idea
Domineering stresses the bullying urge to control others; imperious stresses the lofty assumption of authority — commanding as if by natural right.