Dictate means to speak words aloud for someone else to write down. A doctor might dictate notes about a patient's visit while a nurse types them into a computer. A busy executive might dictate a letter to an assistant, speaking the words that need to be written. Before recording devices existed, writers sometimes dictated their stories to secretaries who would capture every word.

The word also means to command or control what happens. A coach might dictate the team's strategy during a game. Weather can dictate whether your field trip gets canceled. When someone tries to dictate the rules of a game without letting others have a say, they're acting bossy and controlling.

A dictator is a ruler who has complete power over a country and doesn't allow citizens to participate in decisions. Unlike presidents or prime ministers in democracies, who must follow laws and respect citizens' rights, dictators make all the rules themselves.

Notice how both meanings involve one person or thing determining what others must do or write: either the words on a page or the rules everyone must follow.