cortex
Americannoun
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Anatomy, Zoology.
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the outer region of an organ or structure, as the outer portion of the kidney.
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the cerebral cortex.
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Botany.
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the portion of a stem between the epidermis and the vascular tissue; bark.
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any outer layer, as rind.
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Mycology. the surface tissue layer of a fungus or lichen, composed of massed hyphal cells.
noun
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anatomy the outer layer of any organ or part, such as the grey matter in the brain that covers the cerebrum ( cerebral cortex ) or the outer part of the kidney ( renal cortex )
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botany
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the unspecialized tissue in plant stems and roots between the vascular bundles and the epidermis
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the outer layer of a part such as the bark of a stem
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The outer layer of an organ or body part, such as the cerebrum or the adrenal glands.
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The region of tissue lying between the epidermis (the outermost layer) and the vascular tissue in the roots and stems of plants. It is composed of collenchyma, parenchyma, and sclerenchyma. In roots the cortex transfers water and minerals from the epidermis to the vascular tissue, which distributes them to other parts of the plant. The cortex also provides structural support and stores food manufactured in the leaves.
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See illustration at xylem
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of cortex
1650–60; < Latin: bark, rind, shell, husk
Explanation
The cortex refers to the outer layer of an organ or structure in the body, like the brain, where it plays a crucial role in processing information and thoughts. The cortex in any organ helps to protect it and make sure it functions properly. For example, the brain's cerebral cortex is crucial for high-level functions like memory, attention, thought, and consciousness. However, the term isn't exclusive to the brain; the kidney and adrenal glands also have a cortex essential to their operation. In each case, the cortex plays an important role in maintaining the organ’s overall health.
Vocabulary lists containing cortex
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
OL is a tetracyclic triterpenoid isolated from Phellodendri cortex.
From Science Daily ● Jul. 23, 2026
According to Riesenhuber, transferring a well-learned skill into the temporal cortex frees the prefrontal cortex to focus on new challenges, allowing existing knowledge to serve as the foundation for future learning.
From Science Daily ● Jul. 12, 2026
Early in learning, the sorting task primarily activated the prefrontal cortex, the region responsible for executive functions such as planning, reasoning, and conscious decision-making.
From Science Daily ● Jul. 12, 2026
At the same time, your brain’s amygdala, or fear and emotion center, calms down and its prefrontal cortex, which governs rational thought, amps up.
From The Wall Street Journal ● Jun. 27, 2026
Skills that you think should be in the same brain patch are scattered about in different places in the cortex.
From "Phineas Gage" by John Fleischman
"Both the frontal and posterior temporal cortexes disrupt semantic integration, which we see happen in individuals with various aphasias," Murphy said.
From Science Daily ● Oct. 24, 2023
The hypothesis that a drug could protect other patients’ entorhinal cortexes requires more research.
From New York Times ● May 15, 2023
But Rego, who has practiced psychiatry for three decades, takes the unique approach of examining with specificity the impact of 21st century life on our magnificent, misunderstood prefrontal cortexes.
From Salon ● Dec. 13, 2021
A select number of Americans, it should be noted, don’t even own a flat-screen, tablet or other instrument of destruction delivering all this rottery into our cerebral cortexes.
From Seattle Times ● Aug. 29, 2021
“In fact, it is one of the largest lateral prefrontal cortexes I’ve ever seen. Yet the orbitofrontal cortex is remarkably small. What do these two facts indicate?”
From "Insurgent" by Veronica Roth
Extensive preclinical work in the motor and visual cortices was carried out with Dr. Tolias and Bijan Pesaran, professor of neurosurgery at the University of Pennsylvania, both recognized leaders in computational and systems neuroscience.
From Science Daily ● Dec. 9, 2025
In fact, neuroimaging studies show the brains of children who eat more processed snack foods are smaller in volume, particularly in the frontal cortices, than those of children who eat a more healthful diet.
From Salon ● May 28, 2024
The workspace is a network of cortical neurons in the front of the brain, with long-range projections to similar neurons distributed all over the neocortex in prefrontal, parietotemporal and cingulate associative cortices.
From Scientific American ● Sep. 8, 2023
In one 2022 study, Fani, Harnett and their colleagues reported that among 81 Black women who had experienced trauma, those who reported experiencing more racial discrimination showed proportionally thinner gray matter in the cingulate cortices.
From Washington Post ● Feb. 16, 2023
Do the cortices not enter into lamentatory conversation, taking the impress of exteriorities?
From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume I: The Pox Party" by M.T. Anderson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
