jellyfish

noun jel·ly·fish \ ˈje-lē-ˌfish \

|Updated on: 23 Jun 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

The appearance of a large numbers of jellyfish isn't uncommon.

— amanda watts, CNN, "More than 800 people were stung by jellyfish along Florida beaches in three days," 13 June 2018
Over 800 people who flocked to Central Florida beaches over the weekend and into Monday walked away with painful jellyfish stings, according to multiple outlets.

— caitlin keating, PEOPLE.com, "Over 800 People Stung by Jellyfish at Central Florida Beaches in Only Three Days," 13 June 2018
More than 1,000 beachgoers in Florida have been treated for jellyfish stings since Saturday, Volusia County Beach Safety officials said.

— madeline farber, Fox News, "Jellyfish stings causes hundreds of Florida beachgoers to be treated," 13 June 2018
Lifeguards treated 523 people on Sunday while 107 beachgoers were treated for jellyfish stings on Saturday.

— CBS News, "Florida lifeguards treat more than 600 people for jellyfish stings in two days," 13 June 2018
More than 600 people were treated for jellyfish stings this weekend, according to beach safety officials.

— n'dea yancey-bragg, USA TODAY, "Florida lifeguards treat more than 800 for jellyfish stings. Here's what to do if you get stung.," 12 June 2018
After claiming your isle, fish for trophy bass, water-ski, scuba-dive in search of rare freshwater jellyfish, or paddle the 16-mile Ouachita Geo Float Trail, which traces the intricate sedimentary rocks along the shoreline.

— the editors, Outside Online, "North America's 16 Best, Most Overlooked Beaches," 1 June 2018
Some even compared the style, which showcases thinner strands coming out from under a blunt bob, to a jellyfish.

— kaleigh fasanella, Allure, "This Half-Long, Half-Short Haircut Is Sparking a Lot of Feelings on Instagram," 30 May 2018
Beachgoers know to look for jellyfish and sharks, but bacteria?

— danielle garrand, CBS News, "South Carolina offiicials give bacteria warning for Atlantic Ocean after Alberto's heavy rains," 31 May 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

in the meaning defined at sense 1a

See Words from the same year

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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