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

The research focuses on how networks of white matter connections allow different brain regions to communicate, supporting thinking, decision making, and behavior.

From Science Daily • Jan. 3, 2026

"The brain achieves this by leveraging its white matter connectivity to share information across regions, and this integration is crucial for human behavior."

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

The second epoch, adolescence, is marked by continued growth of white matter.

From Science Daily • Dec. 1, 2025

The wound should begin to discharge white matter on the second day in hot weather or the third in cold, and from that time a good recovery may be expected.

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