Definition

the typically free-swimming, bell-shaped, usually sexually-reproducing solitary or colonial form of a cnidarian in which the whorls of tentacles lined with nematocysts arise and hang down from the margin of the nearly transparent, gelatinous bell medusa
especially a large medusa characteristic of the siphonophores and scyphozoans (such as the sea nettle or box jellyfish)
siphonophore
ctenophore
a person lacking backbone or firmness

Illustration

jellyfish 1a

Synonyms & Antonyms

Synonyms

Antonyms

Examples

//a jellyfish who was afraid to tell her boss that her latest brainstorm was just plain bad

First Known Use

1818, in the meaning defined at sense 1a

jellyfish

noun

Synonyms & Antonyms