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.
Creatures without hard shells or bones, such as jellyfish, almost never survive in the fossil record.
From Science Daily • Jan. 27, 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
The 28-year-old revealed her outfit was originally inspired by a jellyfish, which she saw in a book while reading to her two-year-old daughter.
From BBC • Jan. 20, 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
I trail slightly behind my parents and Connor, who is still obsessed with jellyfish, and is now going on and on about how he hopes we see some floating in the water.
From "The Sea in Winter" by Christine Day
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.
