white matter

American  

noun

Anatomy.

1. nerve tissue, especially of the brain and spinal cord, which primarily contains myelinated fibers and is nearly white in color.

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white matter British  

noun

1. Technical name: substantia alba.  the whitish tissue of the brain and spinal cord, consisting mainly of myelinated nerve fibres Compare grey matter

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white matter Scientific  

1. The whitish tissue of the vertebrate brain and spinal cord, made up chiefly of nerve fibers (axons) covered in myelin sheaths.

2. Compare gray matter

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Etymology

Origin of white matter

First recorded in 1830–40

Compare meaning

How does white-matter compare to similar and commonly confused words? Explore the most common comparisons:

• gray matter vs. white matter

Example Sentences

Among participants with mild cognitive impairment, the connection between Alzheimer's related biochemicals and enlarged perivascular spaces was stronger than the connection with white matter damage.

From Science Daily • Jan. 3, 2026

The scans helped show white matter, the fatty substance that insulates the nerve fibers connecting brain regions.

From The Wall Street Journal • Dec. 23, 2025

A new preclinical study from investigators at Weill Cornell Medicine reports that hypertension disrupts blood vessels, neurons and white matter in the brain long before blood pressure rises to detectable levels.

From Science Daily • Nov. 24, 2025

These signs, known as white matter hyperintensities, are small bright spots that appear on brain scans and are thought to reflect areas of tissue damage.

From Science Daily • Oct. 29, 2025

It is composed of the same substances as the brain; but the arrangement is exactly reversed, the white matter encompassing or surrounding the gray matter instead of being encompassed by it.

From A Treatise on Physiology and Hygiene For Educational Institutions and General Readers by Hutchison, Joseph Chrisman