(Type of indument) cobwebby, tangled cottony, the hairs in several directions and tangling.
Slender white loosely tangled hairs; cobwebby.
The middle of the three membranes covering the brain.
The middle of the three membranes covering the brain and spinal cord, which has a fine, almost cobweblike, texture. Between it and the pia mater within lies the subarachnoid space, containing cerebrospinal fluid and large blood vessels; the membrane itself has no blood supply.
One of the protective membranes enveloping the spinal cord and brain; the arachnoid membrane serves as the secondary layer.