white matter

noun

: neural tissue especially of the brain and spinal cord that consists largely of myelinated nerve fibers bundled into tracts, has a whitish color, and typically underlies the cortical gray matter

Examples of white matter in a Sentence

Recent Examples on the Web

Diverse areas can be linked together by edges representing the brain’s structural connections: thick bundles of tubular wires called white matter tracts that tie together brain regions. —Max Bertolero, Scientific American, 1 July 2019

This helped researchers to identify the brain’s six cortical layers and white matter. —Isabel Fraser, WIRED, 15 Aug. 2024

Compared to people without depression or migraine, those with both had lower overall volume, decreased gray and white matter, and less cerebrospinal fluid.5 Serotonin: Both conditions feature low levels of serotonin. —Mark Gurarie, Verywell Health, 14 Aug. 2024

Finally, the white matter in our brains deteriorates over time. —Kevin Cooke, Orlando Sentinel, 20 July 2024

Word History

First Known Use

1674, in the meaning defined above

Kids Definition

white matter

noun

: whitish nerve tissue especially of the brain and spinal cord that consists largely of nerve fibers enclosed in a fatty material and that lies under the gray matter

Medical Definition

white matter

noun

: neural tissue especially of the brain and spinal cord that consists largely of myelinated nerve fibers bundled into tracts, has a whitish color, and typically underlies the gray matter