Definition
Arachnidian refers to anything related to arachnids, a class of arthropods that includes spiders, scorpions, mites, and ticks. Think of it as anything 'spider-like' or related to its relatives. They are characterized by having eight legs and two body segments. The study of arachnids is called arachnology. They play various roles in ecosystems. Some are venomous, while others are harmless.