One way to hold this word: picture one person at the top whose word simply ends the matter. There is nobody above them and nobody who can say no. Orders travel in one direction only, . That picture does not change when the word moves from a country to an office; only the size of the room changes.
The word is built from dictator plus -ial, so its literal reading is simply of the dictator type.
字面上是 dictator（獨裁者）加上 -ial（……的），也就是「獨裁者那一型的」。這條線索很直接：不管拿來講國家還是講人，說的都是同一件事——像獨裁者一樣，說了就算。
Wiktionary etymology for dictatorial (packet evidence): From dictator + -ial.
Two branches
國家層次：真的握有全部權力
這是這個字最原本的位置：畫面裡那個站在最上面的人，真的就是一國的統治者。
adjective · C1
Describing a government, ruler or system that holds complete power over a country, so that one person or a small group decides everything and other people have no real way to refuse.
獨裁的
日常層次：把身邊的人當下屬使喚
同一個畫面縮小到一間辦公室、一個球隊、一張餐桌。權力不是真的，但「說了就算、不給你回話」的感覺一模一樣。
adjective · C1
Describing a person, or the way they speak and act, who keeps telling other people what to do and expects to be obeyed, without listening to them or giving a fair reason.
專斷霸道的