- nerve tissue, especially of the brain and spinal cord, which primarily contains myelinated fibers and is nearly white in color.Compare gray matter(def 1).
Origin of white matter
First recorded in 1830–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the whitish tissue of the brain and spinal cord, consisting mainly of myelinated nerve fibresTechnical name: substantia alba Compare grey matter
- Whitish nerve tissue, especially of the brain and spinal cord, chiefly composed of myelinated nerve fibers and containing few or no neuronal cell bodies or dendrites.alba substantia alba white substance
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- The whitish tissue of the vertebrate brain and spinal cord, made up chiefly of nerve fibers (axons) covered in myelin sheaths. Compare gray matter.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.