arachnid

noun

arach·​nid ə-ˈrak-nəd 

-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

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

Arizona's dry climate and vast expanses of desert terrain create suitable habitats for these arachnids. —Tiffany Acosta, The Arizona Republic, 9 Aug. 2024

The yellow and gray-colored arachnids are originally from east Asia. —Solcyré Burga, TIME, 7 June 2024

Yet even those striking moments of Tarak’s (Staz Nair) taming the Gryphon and Nemesis’s (Bae Doona) battling the maternal arachnid Harmada (Jena Malone) don’t cohere. —Armond White, National Review, 7 Aug. 2024

Arizona's hot, dry climate provides an ideal environment year round for many bugs, including ticks, cicadas, palo verde beetles and arachnids such as Joro spiders, black widows and lots of scorpions (including bark scorpions). —Tiffany Acosta, The Arizona Republic, 17 July 2024

Word History

First Known Use

1826, in the meaning defined above

Kids Definition

arachnid

noun

arach·​nid ə-ˈrak-nəd 

-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