s. LGPN

1. an absolute sovereign , unlimited by law or constitution, [Herdotus Historicus (Refs 5th c.BC), Aeschulus Tragicus (6th/5th c.BC)], etc.: not applied to old hereditary sovereignties βασιλεῖαι); such as those of [Homer (8th/7th c.BC)] or of Sparta; for the term rather regards the irregular way in which the power was gained , than the way in which it was exercised , being applied to the mild Pisistratus, but not to the despotic kings of Persia. However, the word soon came to imply reproach, like our tyrant , [Plato Philosophus (5th/4th c.BC)], etc.
2. in a wider sense, the tyrant's son , or any member of his family , [Sophocles Tragicus (Refs 5th c.BC)]:—;so, ἡ τύραννος was both the queen herself or a princess , [Euripides (Refs 5th c.BC)]
3. τύραννος, ον, as adjective kingly, royal , [variant datesTragica Adespota
4. imperious, despotic , [Thucydides (Refs 5th c.BC)]; τύραννα δρᾶν [Sophocles Tragicus (Refs 5th c.BC)]
τύραννος is probably from same Root as κύριος, κοίρανος. (ML)