Medusa was the famous Gorgon slain by Perseus. She was loved by Poseidon and was pregnant by him when Perseus killed her. Her name is the feminine of medeon or medon, so therefore mean 'ruler', 'queen' (medeousa).

This is a different kind of name to those of the other Gorgons (Euryale, 'wide sea' and Stheno, 'strength') since it denotes a direct 'human' status or position. For this reason, and to align it with the more allusive epithets of the other Gorgons, we could consider deriving Medusa's name from medea, 'cunning'. 'Ruler', however, is the popular explanation of her name.