- A class of chelicerate arthropods that includes spiders, scorpions, mites, and ticks. They have become adapted for a terrestrial life and possess book lungs and tracheae, and many have silk or poison glands.More example sentences
- The Arachnida include the terrestrial chelicerates that everyone is familiar with, and that nearly everyone would rather not be too familiar with: spiders, ticks and mites, and scorpions (Scorpiones).
- Ticks belong to the class Arachnida, which counts mites, spiders and scorpions among its members.
- However, they were not true spiders, nor necessarily ancestral to them, but represented independent offshoots of the Arachnida.
modern Latin (plural), from Greek arakhnē 'spider'.
More definitions of ArachnidaDefinition of Arachnida in:
- The British & World English dictionary