medusa

noun

me·​du·​sa mi-ˈdü-sə 

-ˈdyü-,

-zə

1

capitalized [Latin, from Greek Medousa] : a mortal Gorgon who is slain when decapitated by Perseus

2

plural medusae mi-ˈdü-ˌsē 

-ˈdyü-,

-ˌzē,

-ˌsī,

-ˌzī

also medusas [New Latin, from Latin] : the typically free-swimming, bell-shaped, usually sexually-reproducing, solitary or colonial form of a cnidarian (such as an obelia, box jellyfish, or sea nettle) in which nematocyst-studded tentacles arise and hang down from the margin of the nearly transparent, gelatinous bell see jellyfish

medusan

mi-ˈdü-sᵊn 

-ˈdyü-

-zᵊn

adjective or noun

medusoid

mi-ˈdü-ˌsȯid 

-ˈdyü-

-ˌzȯid

adjective or noun

Examples of medusa in a Sentence

Recent Examples on the Web

In its medusa form, the jellyfish grows to up to 25mm in diameter, about the size of a nickel coin. —Keith Matheny, Freep.com, 6 Aug. 2025

The polyp stage is a precursor to the medusa stage, Folino-Rorem said, when jellyfish are more visible. —Maya Wilkins, Chicago Tribune, 28 Feb. 2025

Jelly Fish with a Red Cross In 2024, an international research team discovered a new species of medusa jellyfish in the Pacific Ocean. —Monica Cull, Discover Magazine, 25 Dec. 2024

The polyps later morph into the recognizable, free-floating jellyfish forms known as medusas. —Brian Handwerk, Smithsonian Magazine, 11 Dec. 2024

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for medusa

• medusae
• arethusa
• musa

Kids Definition

medusa

noun

me·​du·​sa mi-ˈd(y)ü-sə 

-zə

plural medusae -ˌsē 

-ˌzē

also medusas

: jellyfish sense 1