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 also had reduced frontal and occipital lobe volume and more damage in the brain's white matter, changes that have been associated with aging, stroke risk, cognitive decline and dementia.

From Science Daily ● Jul. 21, 2026

Using the MRI scans, they measured the volume of gray matter and white matter in each participant's brain while accounting for differences in overall brain size.

From Science Daily ● Jul. 1, 2026

In this new study, researchers noticed that participants scanned within 16 months of infection showed higher levels of inflammatory activity in white matter than those who had been sick for a longer period.

From Science Daily ● May 28, 2026

Importantly, the increased risk was not explained by overall brain shrinkage or damage to white matter.

From Science Daily ● Jan. 15, 2026

He devoted great care, for instance, to the examination of the brain, emphasized the distinction between the gray and white matter, described the corpus callosum, the septum lucidum, the pineal gland and the corpora quadrigemina.

From The Century of Columbus by Walsh, James J.