gray matter

American  

noun

1. Anatomy. nerve tissue, especially of the brain and spinal cord, that contains fibers and nerve cell bodies and is dark reddish-gray.

2. Informal. brains or intellect.

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gray matter Scientific  

1. The brownish-gray tissue of the vertebrate brain and spinal cord, made up chiefly of the cell bodies and dendrites of neurons.

2. Compare white matter

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gray matter Idioms  

1. Brains, intellect, as in If you'd only use your gray matter, you'd see the answer in a minute. This expression refers to actual brain tissue that is gray in color. Agatha Christie's fictional detective, Hercule Poirot, constantly alludes to using the little gray cells for solving a crime. [Late 1800s]

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Etymology

Origin of gray matter

First recorded in 1830–40

Compare meaning

How does gray-matter compare to similar and commonly confused words? Explore the most common comparisons:

• gray matter vs. white matter

Example Sentences

See Examples For:

gray matter

"By studying an underrepresented population and looking beyond gray matter alone, this work brings us closer to identifying the biological and social factors that may protect cognition across the lifespan."

From Science Daily ● Sep. 14, 2026

Together, gray matter and the white matter directly beneath it form closely connected systems that may both contribute to cognitive health.

From Science Daily ● Sep. 14, 2026

Their findings suggest that the condition of the brain's local communication pathways could influence how strongly gray matter loss affects cognition.

From Science Daily ● Sep. 14, 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

Then, out of nowhere, the parrot swoops down, his wings wide, and he grabs me, his talons digging into the ridges and convolutions of my gray matter.

From "Challenger Deep" by Neal Shusterman