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

The researchers were surprised to find that participants with chronic insomnia who reported sleeping more than usual had fewer white matter spots in the brain — areas where small vessel disease may have damaged brain tissue, which have been linked to cerebrovascular disease. —Melissa Rudy, FOXNews.com, 18 Sep. 2025

Participants with insomnia who reported sleeping less than usual in those two weeks had more white matter hyperintensities and amyloid plaques than participants with insomnia who noted no such issues. —Tom Gavin, EverydayHealth.com, 16 Sep. 2025

The team looked for white matter hyperintensities—areas of brain tissue damage linked to small vessel disease—and amyloid plaques, the protein deposits tied to Alzheimer's disease. —Lucy Notarantonio, MSNBC Newsweek, 10 Sep. 2025

Compared with the brain of same-age peers, SuperAgers have fewer activated microglia, the resident immune cells of the brain, in their white matter. —Sandee Lamotte, CNN Money, 7 Aug. 2025

Word History

First Known Use

1674, in the meaning defined above

Rhymes for white matter

• antimatter
• atter
• batter
• blatter
• catarrh
• chatter
• clatter
• fatter
• flatter
• hatter
• latter
• natter

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