Arachnoid

• POS: Adjective, Noun
• HYPHEN: a=rach=noid

CIDE DICTIONARY

Arachnoid, a. [Gr. like a cobweb; spider, spider's web + e'i^dos form.].

•  Resembling a spider's web; cobweblike.  [1913 Webster]
•  Pertaining to a thin membrane of the brain and spinal cord, between the dura mater and pia mater.  [1913 Webster]
•  Covered with, or composed of, soft, loose hairs or fibers, so as to resemble a cobweb; cobwebby.  [1913 Webster]

Arachnoid, n. 

•  The arachnoid membrane.  [1913 Webster]
•  One of the Arachnoidea.  [1913 Webster]

OXFORD DICTIONARY

Arachnoid, n. & adj.
--n. Anat. (in full arachnoid membrane) one of the three membranes (see MENINX) that surround the brain and spinal cord of vertebrates.
--adj. Bot. covered with long cobweb-like hairs.

Etymology

mod.L arachnoides f. Gk arakhnoeides like a cobweb f. arakhne: see ARACHNID