jellyfish
Americannoun
plural
jellyfish,plural
jellyfishes-
any of various marine coelenterates of a soft, gelatinous structure, especially one with an umbrellalike body and long, trailing tentacles; medusa.
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Informal. a person without strong resolve or stamina; an indecisive or weak person.
noun
-
any marine medusoid coelenterate of the class Scyphozoa, having a gelatinous umbrella-shaped body with trailing tentacles
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any other medusoid coelenterate
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informal a weak indecisive person
Etymology
Origin of jellyfish
1700–10; 1910–15 jellyfish for def. 2; jelly + fish
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Researchers at the University of Waterloo have identified the farthest jellyfish galaxy ever observed.
From Science Daily • Mar. 3, 2026
When they open them, a seascape galaxy of stars appears -- the bluish-white flashes of creatures from plankton and jellyfish to shrimp and fish responding to the sub lights.
From Barron's • Jan. 26, 2026
It looks, and feels, very eighties, but if quantum's potential is realised, the metal and wire jellyfish structure in front of me will transform the world, in many ways.
From BBC • Jan. 7, 2026
The last time these researchers spotted this type of “extraordinary octopus,” the creature was also holding part of a jellyfish, which at the time helped scientists understand its surprising diet of gelatinous animals.
From Los Angeles Times • Dec. 12, 2025
Churning up sand, he raced to where the curious puppy was poised to paw at the jellyfish.
From "Dog Squad" by Chris Grabenstein
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
