arachnid

American  

[uh-rak-nid] / əˈræk nɪd /

noun

• arachnids
  plural

1. any wingless, carnivorous arthropod of the class Arachnida, including spiders, scorpions, mites, ticks, and daddy-longlegs, having a body divided into two parts, the cephalothorax and the abdomen, and having eight appendages and no antennae.

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adjective

1. belonging or pertaining to the arachnids.

arachnid British  

/ əˈræknɪd /

noun

1. any terrestrial chelicerate arthropod of the class Arachnida, characterized by simple eyes and four pairs of legs. The group includes the spiders, scorpions, ticks, mites, and harvestmen

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arachnid Scientific  

/ ə-răk′nĭd /

1. Any of various arthropods of the class Arachnida, such as spiders, scorpions, mites, and ticks. Arthropods are characterized by four pairs of segmented legs and a body that is divided into two regions, the cephalothorax and the abdomen.

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Other Word Forms

Derived Forms

• arachnidan
  adjective

Inflected Forms

Nouns

• arachnids
  plural

Etymology

Origin of arachnid

1865–70; < New Latin Arachnida < Greek aráchn ( ē ) spider, spider's web + New Latin -ida -ida

Explanation

Spiders and scorpions are arachnids. It's a class of animals that also includes tiny, many-legged creatures like mites and ticks. Arachnids are arthropods, or spineless animals with segmented bodies and a shell-like covering. They have a lot in common with crustaceans, but arachnids live on land rather than in the water and don't have antennae. Many varieties of scorpion fall into this category, as well as daddy longlegs (also known as harvestmen). The most common arachnid is a spider — and the word itself derives from the Greek arakhnē, "spider or spider web."

Example Sentences

See Examples For:

arachnid arachnids

After his loved ones were made to forget him, the arachnid hero fights crime undercover in this uninspired Marvel movie also featuring Zendaya and Mark Ruffalo.

From The Wall Street Journal ● Jul. 30, 2026

The arachnid hormones in his body are surging, causing his pupils to turn black and his temper to explode.

From Los Angeles Times ● Jul. 30, 2026

"It's the most emotional Spider-Man movie we've ever made, and in some ways, the most grown up," said Holland, who plays the arachnid superhero.

From Barron's ● Apr. 14, 2026

"Almost 90% -- 88.5% to be precise -- of insect and arachnid species have no conservation status," says Figueroa.

From Science Daily ● Mar. 14, 2026

The woman turned arachnid, all silent, stealthy arms.

From "Little Fires Everywhere" by Celeste Ng

More than 6900 species of harvestmen have been identified, making them one of the most diverse groups of arachnids.

From Science Daily ● Jul. 12, 2026

Researchers believe the nocturnal predator developed the unique hunting method to make meals of aggressive ants which are notoriously dangerous - and unusual - prey for arachnids.

From BBC ● Jun. 23, 2026

"Arachnids, in particular, are really missing from conservation; most states don't even protect a single species. We need more data and protection for insects, but also arachnids," says Walsh.

From Science Daily ● Mar. 14, 2026

Golden orb-web spiders are native to southern and east Africa, with the arachnids at Newrotex coming from Madagascar.

From BBC ● Feb. 10, 2026

“I can speak to arachnids, including their king, Anansi, of course,” she said with pride.

From "The Marvellers" by Dhonielle Clayton