What would an educated, bilingual Roman of Nero's time say of Nero to mean that he was a 'tyrant' etc. in our sense—i.e. a bad, unjust, arbitrary ruler—in (a) Latin and (b) Greek?
BACKGROUND
I understand that neither τύραννος, δεσπότης, nor dictātor implies, at least in its primary sense, that the one so named ruled badly. For example, Oedipus was τύραννος without being tyrannical in our sense. Were there other words for the purpose, or had one of the three acquired a secondary meaning?