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

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Compare meaning

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

• gray matter vs. white matter

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Example Sentences

See Examples For:

gray matter

He has even suggested that the company may eventually enable users to beam music straight into their gray matter.

From The Wall Street Journal ● Oct. 16, 2026

This raises the possibility that the condition of the brain's local wiring could help explain why two people with similar amounts of gray matter loss do not necessarily experience the same degree of cognitive decline.

From Science Daily ● Sep. 14, 2026

"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

Participants with lower plasma vitamin C levels tended to have reduced gray matter volume and weaker connectivity within the default mode network.

From Science Daily ● Jul. 1, 2026

It took my altitude-impaired gray matter a minute or two to comprehend that the object was a human body.

From "Into Thin Air" by Jon Krakauer

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