jellyfish

American  

[jel-ee-fish] / ˈdʒɛl iˌfɪʃ /

noun

jellyfish, plural jellyfishes plural

1. any of various marine coelenterates of a soft, gelatinous structure, especially one with an umbrellalike body and long, trailing tentacles; medusa.

2. Informal. a person without strong resolve or stamina; an indecisive or weak person.

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jellyfish British  

/ ˈdʒɛlɪˌfɪʃ /

noun

1. any marine medusoid coelenterate of the class Scyphozoa, having a gelatinous umbrella-shaped body with trailing tentacles

2. any other medusoid coelenterate

3. informal a weak indecisive person

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Other Word Forms

Noun Inflected Forms

• jellyfish
  plural
• jellyfishes
  plural

Etymology

Origin of jellyfish

1700–10; 1910–15 jellyfish for def. 2; jelly + fish

Explanation

A jellyfish is a marine animal with long tentacles that hang down from a bell-shaped body. Many jellyfish are nearly transparent. Jellyfish may look like they're made of jelly, but their bodies are actually 95 percent water. These umbrella-shaped creatures look graceful floating in the water, but they collapse into a flat blob on land. Jellyfish don't have organs, just a simple nervous system and three layers including the elastic, jelly-like mesoglea that gives them their name. In the 19th century, it became fairly common to call a weak person a jellyfish, a figurative usage that's still around today.

Example Sentences

See Examples For:

jellyfish jellyfishes

Both Bunney and McLaren added that it is important not to touch a jellyfish when it is washed up on a beach as it can still sting, even when presumed dead.

From BBC ● Jul. 28, 2026

Bunney described jellyfish as weak swimmers or "passive drifters" which rely on ocean currents to carry them.

From BBC ● Jul. 28, 2026

Bunney, who said she has been stung a lot by jellyfish, compared a mild sting to that of a nettle.

From BBC ● Jul. 28, 2026

Breeding speed also increases with warmer conditions, allowing adult jellyfish to reproduce in large numbers, creating so-called blooms.

From BBC ● Jul. 28, 2026

He twisted around and pushed himself up toward the surface, only seeing at the last second that the jellyfish had drifted above him.

From "Stormbreaker" by Anthony Horowitz

These showed body plans different from any animals alive today, although some seem to be related to worms and jellyfishes.

From Textbooks ● Jan. 1, 2018

“We need to clearly acknowledge that jellyfishes and other gelatinous organisms may be a regular prey for a variety of marine predators.”

From National Geographic ● Sep. 15, 2017

Both squishy and elastic, jellyfishes can snap like a rubber band over a short periods of time span and ooze like goo over longer periods.

From Scientific American ● Jun. 24, 2015

Expect giraffes and zebras, but also Komodo dragons, jellyfishes and newts for a dash of originality.

From The Guardian ● Feb. 1, 2013

The Cambrian period was the time of the establishment of the chief stocks of backboneless animals such as sponges, jellyfishes, worms, sea-cucumbers, lamp-shells, trilobites, crustaceans, and molluscs.

From The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told by Thomson, J. Arthur

Related Words

• coward
• crybaby
• pushover