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

Example Sentences

Recent Examples on the Web One of the deadliest venoms in the world can be found in the flimsy tentacles of this box jellyfish. Christie Wilcox, Discover Magazine, 2 June 2015 The jellyfish’s sting won’t hurt at first, but 4 to 48 hours later, the venom from these tiny jellies—a species of box jellyfish—can cause a syndrome characterized by feelings of impending doom and life-threatening spikes in blood pressure. Discover Magazine, 6 Apr. 2017 The excruciatingly painful sting of a box jellyfish, which can kill a person in under a minute. Elizabeth Hightower Allen, Outside Online, 2 Mar. 2022 You’ve written about the box jellyfish sting, for instance. Elizabeth Hightower Allen, Outside Online, 2 Mar. 2022 In unregulated economies, children are sometimes deputized to harvest box jellyfish for diners. New York Times, 28 Sep. 2021 Not only that, but box jellyfish also distinguish themselves from other species by using sight to keep from bumping into obstacles on the ocean floor. Jason Duaine Hahn,, 19 Mar. 2021 The humble box jellyfish, which has wandered the ocean for at least 500 million years, can kill a human in five minutes flat. Corryn Wetzel, Smithsonian Magazine, 30 Oct. 2020 Stings by certain species of box jellyfish, including Irukandji species, have caused deaths in the Indo-Pacific. Michele Chabin, Washington Post, 5 July 2019 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'box jellyfish.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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 27 Jan. 2023.

Medical Definition

box jellyfish


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