Definition of "Medusa"

On an Attic vase of the middle of the fifth century the head of Medusa in the hand of Perseus is represented as that of a beautiful woman free from any distortion. This led us to conclude (supra, p. 158) that Medusa must have been so represented at Athens in the greater arts even previous to this vase, for the vase-painters never invent such bold novelties for themselves.

1895, Adolf Furtwängler, Eugenie Strong (editor and translator), Masterpieces of Greek Sculpture: A Series of Essays on the History of Art, 2010, page 201

It will be suggested here that the myth of Perseus, involving the decapitation of Medusa, is a narrative version of ritual.

2000, Nannó Marinatos, The Goddess and the Warrior: The Naked Goddess and Mistress of the Animals in Early Greek Religion, page 62

But their depictions of Perseus are remarkably different and demonstrate the ambiguity of Medusa that was seeping into Victorian iconography. In later, Roman versions of the myth, for example Ovid's Metamorphoses, Perseus slays the sea monster with his sword instead of using Medusa’s head to petrify the monster.

2001, Dennis Berthold, “Melville's Medusas”, in Sanford E. Marovitz, Athanasios C. Christodoulou, editors, Melville "Among the nations": Proceedings of an International Conference, Volos, Greece, July 2-6, 1997