arachnoid

[uh-rak-noid] /əˈræk nɔɪd/
adjective
1.
resembling a spider's web.
2.
of or belonging to the arachnids.
3.
Anatomy. of or pertaining to the arachnoid membrane.
4.
Botany. formed of or covered with long, delicate hairs or fibers.
noun
5.
an arachnid.
6.
Anatomy. the serous membrane forming the middle of the three coverings of the brain and spinal cord.
Compare dura mater, meninges, pia mater.
Origin
1745-55; < Neo-Latin arachnoīdes < Greek arachnoeidḗs cobweblike. See arachnid, -oid
Examples from the web for arachnoid
  • arachnoid having a cobwebby appearance with entangled hairs.
British Dictionary definitions for arachnoid

arachnoid

/əˈræknɔɪd/
noun
1.
the middle of the three membranes that cover the brain and spinal cord See meninges
2.
another name for arachnid
adjective
3.
of or relating to the middle of the three meninges
4.
(botany) consisting of or covered with soft fine hairs or fibres
5.
of or relating to the arachnids
Word Origin and History for arachnoid
adj.

"cobweb-like," especially of the membrane around the brain and spinal cord, 1789, from Modern Latin arachnoides, from Greek arakhnoeides "cobweb-like," from arakhne "cobweb" (see arachnid) + -oeides (see -oid).

arachnoid in Medicine

arachnoid a·rach·noid (ə-rāk'noid')
adj.
Resembling a cobweb. Used of the arachnoid membrane covering the brain and spinal cord.

arachnoid in Science
arachnoid
  (ə-rāk'noid')   
The delicate membrane that encloses the spinal cord and brain and lies between the pia mater and dura mater.