Definition of arachnoid

• a. - Resembling a spider's web; cobweblike.
• a. - Pertaining to a thin membrane of the brain and spinal cord, between the dura mater and pia mater.
• a. - Covered with, or composed of, soft, loose hairs or fibers, so as to resemble a cobweb; cobwebby.
• n. - The arachnoid membrane.
• n. - One of the Arachnoidea.
• a. - Resembling a spider's web; cobweblike.
• a. - Pertaining to a thin membrane of the brain and spinal cord, between the dura mater and pia mater.
• a. - Covered with, or composed of, soft, loose hairs or fibers, so as to resemble a cobweb; cobwebby.
• n. - The arachnoid membrane.
• n. - One of the Arachnoidea.