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

Some of the changes, including the reduction in gray matter, remained two years postpartum, while others, such as the white matter increase, were temporary. —Melissa Willets, Parents, 25 Sep. 2024

More white matter means stronger, better-functioning connections. —Sarah Jividen, Verywell Health, 3 Oct. 2024

While grey matter decreases, there were significant increases in white matter, the nerve fibres that connect neurons and help different brain regions communicate. —Chas Newkey-Burden, The Week Uk, theweek, 18 Sep. 2024

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

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