brain

noun
\ ˈbrān How to pronounce brain (audio) \

Definition of brain

 (Entry 1 of 2)

1a : the portion of the vertebrate central nervous system enclosed in the skull and continuous with the spinal cord through the foramen magnum that is composed of neurons and supporting and nutritive structures (such as glia) and that integrates sensory information from inside and outside the body in controlling autonomic function (such as heartbeat and respiration), in coordinating and directing correlated motor responses, and in the process of learning — compare forebrain, hindbrain, midbrain
b : a nervous center in invertebrates comparable in position and function to the vertebrate brain
2a(1) : intellect, mind has a clever brain
(2) : intellectual endowment : intelligence often used in plural plenty of brains in that family
b(1) : a very intelligent or intellectual person
(2) : the chief planner within a group usually used in plural she's the brains behind their success
3 : something that performs the functions of a brain especially : an automatic device (such as a computer) for control or computation

brain

verb
brained; braining; brains

Definition of brain (Entry 2 of 2)

transitive verb

1 : to kill by smashing the skull
2 : to hit on the head

Illustration of brain

Illustration of brain

Noun

brain 1a: 1 cerebral hemisphere, 2 corpus callosum, 3 ventricle, 4 fornix, 5 thalamus, 6 pituitary gland, 7 pons, 8 medulla oblongata, 9 spinal cord, 10 cerebellum, 11 midbrain

In the meaning defined above

Examples of brain in a Sentence

Noun Scientists are learning more about how the human brain works. The left and right sides of the brain have different functions. The other children always teased him about being such a brain. Verb The tree limb fell and nearly brained me.
Recent Examples on the Web: Noun Then there are the internal debriefings that make up Frances’ narration, which capture the febrile workings of the young-woman brain in all their relentless, vulnerable glory. San Diego Union-Tribune, 13 May 2022 The state has spent more than $25 million in legal fees and settlements with former inmates, including a girl who was severely brain-damaged in a suicide attempt that guards were slow to respond to. Sarah Volpenhein, Milwaukee Journal Sentinel, 13 May 2022 One of the characteristics of being human is our large complex brain. Amiee Ball, Forbes, 13 May 2022 Scherer also expressed frustration at the length of an upcoming hearing over whether defense experts can testify that Cruz's brain suffered damage as a result of his birth mother's alcohol abuse. Terry Spencer, Sun Sentinel, 13 May 2022 Experts have speculated that it's associated with problems in the part of an infant's brain that controls breathing and waking. Katherine Dillinger And Jen Christensen, CNN, 13 May 2022 It’s part of a $50 million award from the Break Through Cancer research foundation to five top cancer centers that will work together on cures for pancreatic, ovarian and brain cancers. Meredith Cohn, Baltimore Sun, 13 May 2022 Whatever the case, the human brain is a superb language-decoding machine. Andrew Leland, The New Yorker, 12 May 2022 Neural interfaces can also create bidirectional pathways of communication between brain and machine. New York Times, 12 May 2022 Recent Examples on the Web: Verb They are linked to brain developmental problems in infants and cancer. Katy Stech Ferek, WSJ, 31 Jan. 2022 How will brain stimulation become accessible to all the patients who need it, given how expensive and invasive some treatments are? Isabella Cueto, STAT, 14 Jan. 2022 The researchers contend that this study marks the first time that a machine-learning algorithm has been matched to brain data to explain the workings of a high-level cognitive task. Anna Blaustein, Scientific American, 26 Oct. 2021 Arguably, achieving universal health care and higher education and addressing the nation’s aging water pipe infrastructure (which has yielded a modern-day lead crisis) could be expected to make similar contributions to brain health across decades. Daniel R. George, Scientific American, 25 Aug. 2021 Then of course there’s me, spying on these other women — and some dads, too — instead of keeping tabs on my four kids, one of whom is poised to brain somebody with a stick. Washington Post, 4 June 2021 Biden, who lost his son Beau Biden to brain cancer in 2015, has pledged to make the fight against cancer a key focus of his administration. Dom Calicchio, Fox News, 25 Mar. 2021 The priority is personal to Biden, who lost his son Beau Biden to brain cancer in 2015. Marisa Schultz, Fox News, 20 Feb. 2021 This less average bone and muscle support makes the head and brain more vulnerable to sudden movement and predicts risk for concussion. Bob Roehr, Scientific American, 9 Mar. 2016 See More

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

First Known Use of brain

Noun

before the 12th century, in the meaning defined at sense 1a

Verb

14th century, in the meaning defined at sense 1

History and Etymology for brain

Noun

Middle English, from Old English brægen; akin to Middle Low German bregen brain, and perhaps to Greek brechmos front part of the head

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Time Traveler for brain

Time Traveler

The first known use of brain was before the 12th century

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Dictionary Entries Near brain

braillewriter

brain

brain attack

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Statistics for brain

Last Updated

18 May 2022

Cite this Entry

“Brain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brain. Accessed 24 May. 2022.

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More Definitions for brain

brain

noun
\ ˈbrān How to pronounce brain (audio) \

Kids Definition of brain

 (Entry 1 of 2)

1 : the part of the nervous system that is inside the skull, consists of grayish nerve cells and whitish nerve fibers, and is the organ of thought and the central control point for the nervous system
2 : the ability to think : intelligence
3 : someone who is very smart

brain

verb
brained; braining

Kids Definition of brain (Entry 2 of 2)

: to hit on the head very hard

brain

noun
\ ˈbrān How to pronounce brain (audio) \

Medical Definition of brain

1 : the portion of the vertebrate central nervous system enclosed in the skull and continuous with the spinal cord through the foramen magnum that is composed of neurons and supporting and nutritive structures (as glia) and that integrates sensory information from inside and outside the body in controlling autonomic function (as heartbeat and respiration), in coordinating and directing correlated motor responses, and in the process of learning — see forebrain, hindbrain, midbrain
2 : a nervous center in invertebrates comparable in position and function to the vertebrate brain

More from Merriam-Webster on brain

Nglish: Translation of brain for Spanish Speakers

Britannica English: Translation of brain for Arabic Speakers

Britannica.com: Encyclopedia article about brain

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