Who Was Medusa?

The word medusa has its origin in the Greek mythology where the word has been attributed to a female character that was monstrous. In some of the mythological descriptions she was considered as one of the three gorgon sisters who had goggling eyes, very sharp and protruding fangs and the hair of them was not of normal hair but of venomous snakes.

Her form is always believed as monstrous but some sculptors and vase painters in the fifth century painted her as beautiful being, though she was still terrifying.

In some of the myth she was known as a beautiful nymph and as she had committed the sin of having intercourse in the Athena temple, she faced the ire of the goddess and she had her hair turned into snakes and her face had become so terrible that the mere sight of it could turn anybody into stone.

One of the Gorgons, three sisters (Medusa, Euryale, & Atheno) the 3 sisters were the daughters of Ceto and Phorcrys.  Medusa was the only one of the three that was mortal.  Athena was so angered by Medusa's violation in her temple that she punished Medusa by turning her into a horrifying monster, with hair made from snakes and the ability to turn onlookers into stone.
She was killed by Perseus, who beheaded her in her sleep.  From her spilled blood sprang to life two creatures: The monster Chrysaor, and winged horse Pegasus.

The word Medusa is related to many things however here are two statements regarding "Medusa".
1. (Greek mythology) a woman transformed into a Gorgon by Athena; she was slain by Perseus.
2. one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles.

No the athena myth is correct not the aphrodite one.

To correct that Medusa was a hand Madden to Aphrodite who made the mistake of comparing her beauty to the goddesses in return, she was changed into the snake creature portrait with snakes for hair her look was said to turn anyone who looked into her eyes to stone.

One of the three Gorgons, and the only mortal one.