jellyfish

noun jel·ly·fish \ ˈje-lē-ˌfish \

Updated on: 15 Apr 2018

Definition of jellyfish

1 a : 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

b : siphonophore

c : ctenophore

2 : a person lacking backbone or firmness

See jellyfish defined for English-language learners

See jellyfish defined for kids

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 of jellyfish from the Web

Upstairs, above the VizStudio and the jellyfish breeding lab, hundreds of CalAcademy visitors shuffled into their seats beneath the dome.

— beth spotswood, San Francisco Chronicle, "Team works in twilight zone to bring reef to surface at Cal Academy," 11 Apr. 2018
Walker helmed the creation of puppets representing sea creatures such as jellyfish, stingrays and turtles, which will be placed on stage and throughout the auditorium.

— jeff piorkowski/special to cleveland.com, cleveland.com, "'The Little Mermaid' swims into Mayfield High School auditorium for shows April 13-22," 10 Apr. 2018
Meanwhile, jellyfish float, bubbles rise, Picasso and Klee turn up, fireworks explode, drums beat and cymbals sound. As if suddenly, nine minutes have passed.

— leah ollman, latimes.com, "When is now? Now? Or now? For artist Robin Cameron, time is ultimate brain teaser," 9 Apr. 2018
This season's designs incorporate humpback whales and jellyfish swimming among herring.

— melissa devaughn, Anchorage Daily News, "Iconic in Alaska, classic Xtratuf boot gets a redesign," 31 Mar. 2018
Sean was holding me in the warm, shallow water off Ko Pha Ngan when the jellyfish wrapped around his legs below me.

— shannon leone fowler, The Cut, "The Strange Pregnancy Fact That Helped Me Mourn My Fiancé’s Death," 19 Mar. 2018
Leatherback turtles are nature’s U-boats, 1,500-pound reptiles that can dive to depths of more than half a mile, snatch a jellyfish and stay submerged for more than an hour before resurfacing.

— david fleshler, Sun-Sentinel.com, "Fight begins over fate of leatherback sea turtle," 23 Mar. 2018
Adding to that curiosity is the fact that the plot involves some sort of jellyfish.

— joanna robinson, HWD, "What’s New on Netflix in April," 21 Mar. 2018
The multi-level atrium features a massive series of LED screens that transport you from under the sea (think corals and jellyfish) to far away places.

— jane wooldridge, miamiherald, "Yes, it looks like a condo. But it’s really a cruise ship — with killer views. | Miami Herald," 13 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'jellyfish.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of jellyfish

First Known Use of jellyfish

1841

jellyfish Synonyms

JELLYFISH Defined for English Language Learners

jellyfish

noun

Definition of jellyfish for English Language Learners

: a sea animal that has a very soft body and that can sting

JELLYFISH Defined for Kids

jellyfish

noun jel·ly·fish \ ˈje-lē-ˌfish \

Definition of jellyfish for Students

: a free-swimming sea animal related to the corals that has a nearly transparent jellylike body shaped like a saucer and tentacles with stinging cells

Medical Dictionary

jellyfish

noun jel·ly·fish \ ˈjel-ē-ˌfish \

medical Definition of jellyfish

: 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