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

See Examples For:

white matter

They were also linked to a more rapid buildup of changes in white matter.

From Science Daily ● Aug. 6, 2026

They also showed greater volumes of white matter hyperintensities, which are signs of cerebral small blood vessel disease and have been linked to cognitive decline and dementia.

From Science Daily ● Jul. 21, 2026

Participants who spent a large portion of their workday sitting actually had larger frontal and occipital lobes and lower white matter hyperintensity volumes.

From Science Daily ● Jul. 21, 2026

Surrounding that is white matter, made up of astrocytes and long nerve fibers that carry signals between the brain and the rest of the body.

From Science Daily ● Feb. 13, 2026

A transverse section of the cord reveals that it is composed of white matter externally and of gray matter internally.

From Special Report on Diseases of the Horse by Charles B. Michener