arachnid

noun

arach·​nid ə-ˈrak-nəd How to pronounce arachnid (audio)
-ˌnid
: 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
arachnid adjective

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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 Without a deep freeze, these arachnids and various insect pests don’t die off en masse, Pell says. Jude Coleman, Scientific American, 22 Mar. 2023 About 40 to 60 species of these arachnids live in the Grand Canyon State, according to the Arizona Department of Agriculture. Dina Kaur, The Arizona Republic, 21 June 2023 This jet-black arachnid ranges from 0.2 to 0.5 inches in size and are rarely seen. Cole Sikes Communications and Marketing Specialist Alabama Cooperative Extension System, al, 8 Aug. 2023 Spider monkeys typically consume fruits, leaves, nuts, seeds, and sometimes arachnids and insects. Amaris Encinas, USA TODAY, 4 Aug. 2023 The parasitic arachnids are also noted to be moving further north and higher in altitude as formerly inhospitable terrain warms to their preferred temperature range. Time, 28 July 2023 The camel spider, also recognized as a sun spider and wind scorpion, is one of the most unique arachnids of all time and holds captivating secrets. Jeremy Hillpot, Discover Magazine, 10 June 2023 Hers is one of countless accounts that have fascinated TikTok users who may have previously swatted at or cowered from the misunderstood arachnids. Scottie Andrew, CNN, 25 Mar. 2023 The hissing happens when arachnids rub their body parts together. Jeremy Hillpot, Discover Magazine, 10 June 2023 See More

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

Word History

First Known Use

1826, in the meaning defined above

Time Traveler
The first known use of arachnid was in 1826

Dictionary Entries Near arachnid

Cite this Entry

“Arachnid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/arachnid. Accessed 30 Sep. 2023.

Kids Definition

arachnid

noun
arach·​nid ə-ˈrak-nəd How to pronounce arachnid (audio)
-ˌnid
: any of a class of arthropods including the spiders, scorpions, mites, and ticks and having a segmented body divided into two regions of which the front part bears four pairs of legs but no antennae
arachnid adjective

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