arach·​nid | \ ə-ˈrak-nəd, -ˌnid\

Definition of arachnid

: any of a class (Arachnida) of arthropods comprising chiefly terrestrial invertebrates, including the spiders, scorpions, mites, and ticks, and having a segmented body divided into two regions of which the anterior bears four pairs of legs but no antennae

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Other Words from arachnid

arachnid adjective

Did You Know?

The term arachnid refers to a class of animals that includes spiders, scorpions, mites, and ticks. Most arachnids have a segmented body divided into two regions, with the front part bearing four pairs of legs, but no antennae. They have a hard external skeleton and range in size from the mite, which is 0.003-in (0.08-mm) long, to the 8-in (21-cm) black scorpion of Africa. As arachnids grow, they molt, or shed their skin, several times. Arachnids are primarily carnivorous, but most are unable to digest food internally, instead they inject their prey with digestive fluids, then suck the liquefied remains. Arachnids are found worldwide in nearly every habitat. Some mites and ticks are parasitic and can carry diseases. Venomous spiders and scorpions also may pose a danger to humans, but most arachnids are harmless and prey only on insects.

Examples of arachnid in a Sentence

Spiders, scorpions, mites, and ticks are arachnids.

Recent Examples on the Web

So is this one species of spider the only lactating arachnid, or is this behavior more common than scientists thought? Avery Thompson, Popular Mechanics, "There Is a Spider That Feeds Its Young Delicious Milk, Because Nature Is Scary," 30 Nov. 2018 Six Eyes Add four more eyes to your face for an arachnid aesthetic like Canadian makeup artist Megan Brown. 11. Devon Abelman, Allure, "27 Last-Minute Halloween Costumes You Can Do With Just Makeup," 10 Oct. 2018 Black widow spiders are considered the deadliest arachnids in the U.S., with a venomous bite about 15 times more potent than a rattlesnake's, according to National Geographic. Jennifer Earl, Fox News, "Connecticut woman finds black widow spider in bag of grapes," 18 July 2018 Most scientists assumed spiders simply sail on the wind, but this didn’t explain how the arachnids traveled so far in light winds. Renae Reints, Fortune, "Spiders Can Fly Through the Air for Miles Using Electricity, Study Finds," 6 July 2018 Sméagol, better known as the hobbitses-hating Gollum, is the namesake of yet another arachnid, Landumoema smeagol. Brigit Katz, Smithsonian, "Introducing a Hairy-Footed Shrimp Named After Bilbo Baggins," 13 June 2018 While scientists have long known about ballooning, the mechanisms of this remarkable arachnid ability are not well understood. Brigit Katz, Smithsonian, "Before Soaring Through the Air, Tiny Crab Spiders Study the Wind," 18 June 2018 Eventually, the team ventures deep underground to find an aggressive arachnid-like boss creature, the Swarm Tyrant. Patrick Shanley, The Hollywood Reporter, "'Anthem' Producer Promises Game Will Offer a "Totally Different Experience" Every Time It's Played," 5 July 2018 The culprit is a small arachnid: the lone star tick. Thomas Leavy, CBS News, "Maine on the lookout for ticks that cause red-meat allergy," 25 June 2018

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

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First Known Use of arachnid

1826, in the meaning defined above

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Statistics for arachnid

Last Updated

23 Dec 2018

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Time Traveler for arachnid

The first known use of arachnid was in 1826

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English Language Learners Definition of arachnid

: a kind of animal that has eight legs and a body formed of two parts

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More from Merriam-Webster on arachnid

Rhyming Dictionary: Words that rhyme with arachnid

Nglish: Translation of arachnid for Spanish Speakers Encyclopedia article about arachnid

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