- resembling a spider's web.
- of or belonging to the arachnids.
- Anatomy. of or relating to the arachnoid membrane.
- Botany. formed of or covered with long, delicate hairs or fibers.
- an arachnid.
- Anatomy. the serous membrane forming the middle of the three coverings of the brain and spinal cord.
Origin of arachnoid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for arachnoid
Cobwebby, same as arachnoid; bearing hairs like cobwebs or gossamer.The Elements of Botany
The arachnoid is a thin membrane which lies beneath the dura mater.A Practical Physiology
Albert F. Blaisdell
All the ventricles of the brain were dilated with serum, and there was a good deal of effusion into the arachnoid and pia mater.
In Cortinarius, the veil is composed of arachnoid threads, and the spores are rusty.Fungi: Their Nature and Uses
Mordecai Cubitt Cooke
When traced through the dura mater they are found to spring from the arachnoid.
- of or relating to the middle of the three meninges
- botany consisting of or covered with soft fine hairs or fibres
- of or relating to the arachnids
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for arachnoid
Online Etymology Dictionary, © 2010 Douglas Harper
- Resembling a cobweb. Used of the arachnoid membrane covering the brain and spinal cord.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- The delicate membrane that encloses the spinal cord and brain and lies between the pia mater and dura mater.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.