person of paramount authority; supreme wielder of power
Refers to the individual holding the highest decision-making power in a government, organization, or regime. Often used in political or historical contexts.
In a dictatorship, the supreme ruler decides everything.
As the person with the highest authority in the company, he made the final decision.
Compound of 最高 (highest) + 権力 (power, authority) + 者 (person). The exact historical derivation is uncertain, but the word follows a common pattern for forming agent nouns in modern Japanese.