box jellyfish


variants or less commonly box jelly
: any of various cube-shaped scyphozoan jellyfishes (order or suborder Cubomedusae) of tropical and warm marine waters that inflict a painful and sometimes fatal sting
especially : an extremely venomous box jellyfish (Chironex fleckeri) of Australia that has a bell that may reach over 11 inches (28 centimeters) in width with tentacles that may reach a length of over 78 inches (2 meters) : sea wasp
Found in the waters off northern Australia, the box jellyfish … is not the only marine invertebrate to use venom, but it is the possessor of arguably the most lethal venom in the world. Jamie Seymour

Examples of box jellyfish in a Sentence

Recent Examples on the Web Jack Barnes, a Queensland physician, eventually narrowed down the suspects to a species of tiny, nearly transparent box jellyfish. Nathaniel Scharping, Discover Magazine, 1 Nov. 2017 In a new study, researchers showed that the Caribbean box jellyfish can actually learn from experience, no brain required. Rachel Feltman, Popular Science, 22 Nov. 2023 These experiments provide evidence that box jellyfish are capable of associative learning, or the process of linking two unrelated stimuli together. Sarah Kuta, Smithsonian Magazine, 25 Sep. 2023 Scientists weren’t surprised the Caribbean box jellyfish—a smaller, non-lethal counterpart to the deadly Australian box jellyfish—could learn. Sarah Kuta, Smithsonian Magazine, 25 Sep. 2023 In the warm waters of the Caribbean, box jellyfish carefully dodge the roots of mangroves while hunting for small crustaceans to eat. Sarah Kuta, Smithsonian Magazine, 25 Sep. 2023 Poisonous Caribbean box jellyfish can learn at a far more complex level than ever imagined, despite only having 1,000 nerve cells and no centralized brain, according to new research from the University of Copenhagen. Melissa Rudy, Fox News, 24 Sep. 2023 The area is heavily populated with crocodiles, sharks, and deadly box jellyfish. Nina Derwin, Redbook, 16 Aug. 2023 Even with just 1,000 neurons active at a time and no central brain, Caribbean box jellyfish (Tripedalia cystophora) can learn from experience, researchers argue in a new paper published September 22 in the journal Current Biology. Meghan Bartels, Scientific American, 22 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'box jellyfish.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


from its square shape

First Known Use

1960, in the meaning defined above

Time Traveler
The first known use of box jellyfish was in 1960

Dictionary Entries Near box jellyfish

Cite this Entry

“Box jellyfish.” Dictionary, Merriam-Webster, Accessed 20 May. 2024.

Medical Definition

box jellyfish


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