1. Resembling a spider in form or movement
   "The scorpion's arachnoid features include eight legs and a pair of pedipalps";
   - arachnidian, spidery, spiderlike, spiderly

1. The middle of the 3 meninges
   "The arachnoid membrane contains cerebrospinal fluid";
   - arachnoid membrane
    
2. Air-breathing arthropod characterized by eight legs, simple eyes, and no antennae or wings; includes spiders, scorpions, and mites
   "The arachnoid built an intricate web in the corner";
   - arachnid

Derived forms: arachnoids

Type of: arthropod, meninges, meninx

Part of: Arachnida, class Arachnida, leptomeninges

Encyclopedia: Arachnoid