gray matter


Definition of gray matter

1 : neural tissue especially of the brain and spinal cord that contains nerve-cell bodies as well as nerve fibers and has a brownish-gray color

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Examples of gray matter in a Sentence

she's got the gray matter to figure that equation out

Recent Examples on the Web

As research into our mysterious gray matter continues to explode, scientists are getting ever closer to understanding what creates a calm, contented and happy brain. Sandee Lamotte, CNN, "Want to live longer? Be an optimist, study says," 26 Aug. 2019 The first technique was standard 3D fluid-attenuated inversion recovery (FLAIR) imaging that allowed the team to calculate the volume of white and gray matter throughout each patient’s brain. Beth Mole, Ars Technica, "Brain imaging weirdness adds to Cuba “health attack” mystery," 24 July 2019 Acute flaccid myelitis is a rare but serious condition that affects the nervous system -- specifically, the area of the spinal cord called gray matter. Michael Nedelman, CNN, "11 cases of polio-like illness AFM confirmed in eight states in 2019, CDC says," 9 July 2019 In 2012, Sikela and collaborators used special tools to count the number of copies in healthy people and discovered that the more copies someone has, the larger their gray matter, the portion of the brain made up of nerve cells. Quanta Magazine, "A Missing Genetic Link in Human Evolution," 2 Jan. 2014 Preserved inside a glass container filled with a solution of formaldehyde, the chunk of gray matter floats effortlessly, as though suspended in time. Jennifer Nalewicki, Smithsonian, "How One Museum Is Giving a Voice to Former Mental Health Patients," 2 July 2019 Returning to Earth helped the gray matter mostly bounce back but seemed to cause shrinkage in white matter, which connects parts of the brain. National Geographic, "What happens to brains in space, and more breakthroughs," 12 June 2019 Paleoanthropologists are rethinking a basic idea about how our gray matter evolved. Gemma Tarlach, Discover Magazine, "20 Things You Didn't Know About ... The Year in Science," 1 Jan. 2019 People who eat fish regularly also have more gray matter in the brain centers that control memory and emotion. Orthocincy,, "Benefits of eating fish," 19 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'gray matter.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of gray matter

1809, in the meaning defined at sense 1

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Statistics for gray matter

Last Updated

14 Sep 2019

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Time Traveler for gray matter

The first known use of gray matter was in 1809

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More Definitions for gray matter

gray matter


English Language Learners Definition of gray matter

: the tissue that makes up the brain

gray matter


Medical Definition of gray matter

: neural tissue especially of the brain and spinal cord that contains cell bodies as well as nerve fibers, has a brownish gray color, and forms most of the cortex and nuclei of the brain, the columns of the spinal cord, and the bodies of ganglia

called also gray substance

More from Merriam-Webster on gray matter

Rhyming Dictionary: Words that rhyme with gray matter

Thesaurus: All synonyms and antonyms for gray matter Encyclopedia article about gray matter

Comments on gray matter

What made you want to look up gray matter? Please tell us where you read or heard it (including the quote, if possible).


to spread over or through

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