arbiter
supreme authority

The convention is vested with the supreme authority of the Society.

The police, at least a good number of them, have become the supreme authority.

He held the supreme authority of Serbs at that time.

The voters assembly is the supreme authority in the congregation.

Maybe, just one more time, we could pretend the supreme authority was fine but staying out of sight.

Senate has the supreme authority on all academic matters of the University.

The supreme authority, however, was the commander of the French troops.

The supreme authority on the island had a council consisting of 20 members who held office for life.

The council was the government of the country, but also the supreme judicial authority.

On 13 May the resolution was approved by the supreme authority of the police.