The Greek name of the Gorgon Medusa (Medousa) means “guardian,” from medeiun (“to protect, rule over”). Medusa is also the genus name for jellyfish, comparing their tentacles to the snakes in place of her hair, and their sometimes-deadly sting to her ability to turn those who saw her face to stone.
note that the character above is not Medusa, but inspired by her
The three Gorgon sisters were Medusa, Euryale, and Stheino, all of whom had serpents for hair and could turn people to stone with a look. “Gorgon” is from the Greek Gorgones (singular Gorgo) meaning “the grim ones,” from gorgós “terrible, fierce, grim” (or “dreadful,” according to this entry), which appears to come from the same root as the Sanskrit word garğ, defined as a guttural sound, similar to the growling of a beast.
Useless Etymology 