The story
- Proto-Indo-European*deyḱ-
- Proto-Indo-European*déyḱeti
- Proto-Italic*deikō
- Latindīcō
- Latindictō
- Latindictātor
- English todaydictator
Borrowed from Latin dictātor (“a chief magistrate”), from dictō (“dictate, prescribe”), from dīcō (“say, speak”). By surface analysis, dictate + -or, literally “one who dictates”. Compare Old English tictator (“absolute ruler of the Roman Republic”).
Etymology from Wiktionary, CC BY-SA 4.0.