tyrant tyrant /ˈtaɪrənt/

noun

1. () A cruel and oppressive dictator  ( autocrat , despot , tyrant )
   a cruel and oppressive dictator
   
2. Any person who exercises power in a cruel way  ( tyrant )
   any person who exercises power in a cruel way
    His father was a tyrant
   his father was a tyrant
   
3. In ancient Greece, a ruler who had seized power without legal right to it  ( tyrant )
   in ancient Greece, a ruler who had seized power without legal right to it