2. (Anat.)

Defn: Pertaining to a thin membrane of the brain and spinal cord, between the dura mater and pia mater.

3. (Bot.)

Defn: Covered with, or composed of, soft, loose hairs or fibers, so as to resemble a cobweb; cobwebby.

ARACHNOID
A*rach"noid, n.

1. (Anat.)

Defn: The arachnoid membrane.

2. (Zoöl.)

Defn: One of the Arachnoidea.

ARACHNOIDAL
Ar`ach*noid"al, a. (Anat.)