Illustration of jellyfish
- jellyfish 1a
jellyfish
noun
jel·ly·fish
ˈje-lē-ˌfish 
1
a
: 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)
b
c
2
: a person lacking backbone or firmness
Examples of jellyfish in a Sentence
a jellyfish who was afraid to tell her boss that her latest brainstorm was just plain bad
Recent Examples on the Web
My candidacy is a symbol of the end of the weak-kneed, feckless Republican leadership of Mitch McConnell, and the spineless swamp jellyfish that are in the United States Senate representing the Republicans.
—
Billal Rahman, MSNBC Newsweek, 22 Oct. 2025
Boissevain’s nature photography captures these in-transition landscapes in vivid hues and alien geometries, from close-ups of jellyfish-like crystal deposits to aerial shots of what scans like the surface of Mars.
—Randy McMullen, Mercury News, 16 Oct. 2025
The production was plagued by hurricanes, tsunami warnings, stinging jellyfish and several injuries — including Costner, who almost died while riding out a storm stranded atop a mast after his safety line had snapped.
—Peter Kiefer, HollywoodReporter, 8 Oct. 2025
While Nathan runs around pulling his hair and Josh finds a way to plate nuts with eggs, Max tries to amuse himself and Aesha by playing with a jellyfish.
—Rafaela Bassili, Vulture, 7 Oct. 2025
See All Example Sentences for jellyfish
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Billal Rahman, MSNBC Newsweek, 22 Oct. 2025
Boissevain’s nature photography captures these in-transition landscapes in vivid hues and alien geometries, from close-ups of jellyfish-like crystal deposits to aerial shots of what scans like the surface of Mars.
—Randy McMullen, Mercury News, 16 Oct. 2025
The production was plagued by hurricanes, tsunami warnings, stinging jellyfish and several injuries — including Costner, who almost died while riding out a storm stranded atop a mast after his safety line had snapped.
—Peter Kiefer, HollywoodReporter, 8 Oct. 2025
While Nathan runs around pulling his hair and Josh finds a way to plate nuts with eggs, Max tries to amuse himself and Aesha by playing with a jellyfish.
—Rafaela Bassili, Vulture, 7 Oct. 2025
See All Example Sentences for jellyfish
Cite this Entry
“Jellyfish.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/jellyfish. Accessed 29 Oct. 2025.
Copy CitationKids Definition
jellyfish
noun
jel·ly·fish
ˈjel-ē-ˌfish
1
: any of numerous free-swimming coelenterate animals that reproduce sexually and have a jellylike, saucer-shaped, and usually nearly transparent body and tentacles with stinging cells
2
: any of various sea animals that resemble a jellyfish
Medical Definition
jellyfish
noun
jel·ly·fish
ˈjel-ē-ˌfish
: a free-swimming marine coelenterate that is the sexually reproducing form of a hydrozoan or scyphozoan and has a nearly transparent saucer-shaped body and extensible marginal tentacles studded with stinging cells
Love words? Need even more definitions?
Merriam-Webster unabridged
Share