Arachnoid

Arachnoid may refer to:


 * Relating to arachnids
 * Arachnoid (astrogeology), a geological structure found only on the planet Venus
 * Arachnoid (botany), referring to organs with a cobwebby exterior appearance
 * Arachnoid granulation, small protrusions of the arachnoid mater
 * Arachnoid mater, a layer of the meninges, membranes that contain the central nervous system