medusa

noun, plural me·du·sas, me·du·sae [muh–doo-see, -zee, –dyoo-] /məˈdu si, -zi, -ˈdyu-/. Zoology.

1. a saucer-shaped or dome-shaped, free-swimming jellyfish or hydra.

noun, plural Me·du·sas. Classical Mythology.

1. the only mortal of the three Gorgons. She was killed by Perseus, and her head was mounted upon the aegis of Zeus and Athena.

noun plural -sas or -sae (-ziː)

1. another name for jellyfish (def. 1), jellyfish (def. 2)
2. Also called: medusoid, medusan one of the two forms in which a coelenterate exists. It has a jelly-like umbrella-shaped body, is free swimming, and produces gametesCompare polyp

noun

1. Greek myth a mortal woman who was transformed by Athena into one of the three Gorgons. Her appearance was so hideous that those who looked directly at her were turned to stone. Perseus eventually slew herSee also Pegasus 1

n.“jellyfish,” 1758, as genus name, from the name of one of the three Gorgons with snakes for hair, whose glance turned to stone him who looked upon it (attested in English from late 14c.). Her name is from Greek Medousa, literally “guardian,” fem. present participle of the verb medein “to protect, rule over” (see Medea). The zoological name was chosen by Linnæus, suggested by the creature’s long tentacles. Related: Medusoid. Plural medusas medusae (mĭ-dōō′sē)

1. A cnidarian in its free-swimming stage. Medusas are bell-shaped, with tentacles hanging down around a central mouth. Jellyfish are medusas, while corals and sea anemones lack a medusa stage and exist only as polyps. Compare polyp.

The best known of the monster Gorgons of classical mythology; people who looked at her would turn to stone. A hero, Perseus, was able to kill Medusa, aiming his sword by looking at her reflection in a highly polished shield.