Webster's Revised Unabridged Dictionary · 1913

Medusa

Medusa , noun

[Latin, from Greek {not transcribed}.]

1.
(Class. Mythology) The Gorgon; or one of the Gorgons whose hair was changed into serpents, after which all who looked upon her were turned into stone.
2.
(Zoology) Any free swimming acaleph; a jellyfish.

The larger medusae belong to the Discophora, and are sometimes called covered-eyed medusae; others, known as naked-eyed medusae, belong to the Hydroidea, and are usually developed by budding from hydroids. See Discophora, Hydroidea, and Hydromedusa.

Collocations (2)
Medusa bud (Zoology) , one of the buds of a hydroid, destined to develop into a gonophore or medusa. See Athecata, and Gonotheca.
Medusa's head (Zoology) , An astrophyton A cluster of stars in the constellation Perseus. It contains the bright star Algol.