cortex

noun

cor·​tex ˈkȯr-ˌteks How to pronounce cortex (audio)
plural cortices ˈkȯr-tə-ˌsēz How to pronounce cortex (audio) also cortexes
1
a(1)
: the outer or superficial part of an organ or bodily structure (such as the kidney, adrenal gland, or cerebellum or a bone)
especially : cerebral cortex
(2)
: the proteinaceous usually pigmented layer of a hair below the cuticle
b
: the outer part of some organisms (such as paramecia)
2
: a plant bark or rind (such as cinchona) used medicinally
3
a
: the typically parenchymatous layer of tissue external to the vascular tissue and internal to the corky or epidermal tissues of a green plant
broadly : all tissues external to the xylem
b
: an outer or investing layer of various algae, lichens, or fungi

Example Sentences

Recent Examples on the Web There is still some surgery, yes, but overall, it is inserted into the top of the brain’s motor cortex via blood vessels. Joshua Hawkins, BGR, 8 Nov. 2022 On the other hand, more recent research using multiple electrodes to stimulate somatosensory cortex in nonhuman primates found that such electrical stimulation could elicit response times slightly faster than natural touch. David Caldwell, The Conversation, 30 Mar. 2022 Some of their brain cells in the entorhinal cortex, an area involved in memory, were larger even than those of individuals who were 20 to 30 years their juniors, per the study. Margaret Osborne, Smithsonian Magazine, 4 Oct. 2022 In fact the prefontal cortex, which manages rational thought, problem-solving and consequences, doesn't fully develop until the mid-20s. Sandee Lamotte, CNN, 20 Sep. 2022 They were especially pronounced in areas such as the parahippocampal gyrus, which is important for encoding and retrieving memories, and the orbitofrontal cortex, which is important for executive function. Ed Yong, The Atlantic, 12 Sep. 2022 Researchers say monitoring chemical changes in the pre-frontal cortex could have practical implications, such as helping detect severe mental fatigue in order to avoid burnout in the workplace. Alex Millson/bloomberg, Time, 11 Aug. 2022 Researchers say monitoring chemical changes in the pre-frontal cortex could have practical implications, such as helping detect severe mental fatigue in order to avoid burnout in the workplace. Alex Millson, Fortune, 11 Aug. 2022 Crucially, some of these atypical developments could only be seen in human neurons growing within the rat cortex, and not in organoid neurons in a dish. Allison Whitten, Quanta Magazine, 12 Oct. 2022 See More

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

Word History

Etymology

Latin cortic-, cortex bark — more at cuirass

First Known Use

circa 1676, in the meaning defined at sense 1a(1)

Time Traveler
The first known use of cortex was circa 1676

Dictionary Entries Near cortex

Cite this Entry

“Cortex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cortex. Accessed 5 Dec. 2022.

Kids Definition

cortex

noun

cor·​tex ˈkȯr-ˌteks How to pronounce cortex (audio)
plural cortices ˈkȯrt-ə-ˌsēz How to pronounce cortex (audio) or cortexes
1
: an outer or surrounding layer of an organ or body part
the cortex of the kidney
especially : the outer layer of gray matter of the cerebrum
2
: the layer of tissue outside the xylem and phloem and inside the corky or epidermal tissues of a vascular plant
also : all tissues external to the xylem

Medical Definition

cortex

noun

cor·​tex ˈkȯr-ˌteks How to pronounce cortex (audio)
plural cortices ˈkȯrt-ə-ˌsēz How to pronounce cortex (audio) also cortexes
1
a
: the outer or superficial part of an organ or body structure (as the kidney, adrenal gland, or a hair)
especially : cerebral cortex
b
: the outer part of some organisms (as paramecia)
2
a
: a plant bark or rind (as cinchona) used medicinally
b
: the peel of any of several fruits
used especially in the writing of medical prescriptions

More from Merriam-Webster on cortex

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!


The Great British Vocabulary Quiz

  • union jack speech bubble
  • Named after Sir Robert Peel, what are British police called?
Spell It

Hear a word and type it out. How many can you get right?

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ