noun
dictator; despot
Refers to a ruler with absolute power, often with negative connotations of oppression.
その国は長年独裁者に支配されていた。
That country was ruled by a dictator for many years.
独裁者は反対意見を一切許さなかった。
The dictator did not allow any dissenting opinions.
暴君 emphasizes cruelty and tyranny, whereas 独裁者 focuses on the concentration of power.
Compound of 独裁 (どくさい, 'dictatorship, autocracy') + 者 (しゃ, 'person'). 独裁 is from 独 (alone) + 裁 (judge, decide).