A form of government where political authority rests with a single leader autocratic or democratic

The correct answer is - autocratic.

The governments where the political authority rests with a single leader is called autocratic government. In this type of governments, the leaders have absolute power in the country, their word is law, and there isn't any institution that monitors or restricts them. In this type of governments there isn't multiple parties from which the people can choose on elections who should be their leader.

This system has largely been abandoned around the world. There isn't a single developed country that has a government like this, but there are some developing or less developed countries that unfortunately are in the hands of such governments.

Examples of such governments are Belarus, Turkmenistan, North Korea.

Autocratic

Explanation:

Allow me to explain some of the terms for government according to the Greek roots the names are based on. "Kratos" in Greek meant "power" or "rule." There was even a Greek god named Kratos that personified the meaning of power or strength. So our terms for government are based on Greek compound words about where the power or strength lied in a society.

"Autocracy" means ""power itself" or "himself." The only one who has power in an autocratic system iss the single leader.

"Democracy" means "rule by the people." Democratic societies are run by the people.

"Theocracy" means "rule by God." Societies that follow a religious leadership claiming to speak for God are seen as theocratic.

"Plutocracy" means "rule by the rich." A society where the wealthiest individuals control all the power is plutocratic.

"Aristocracy" means "rule by the noble or excellent ones." Those who are considered the more elite members of a society govern affairs in an aristocracy.

There are more such terms, but those are some of the main ones stemming from terms the ancient Greeks gave us.