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 pluralplenty of brains in that family
b(1) : a very intelligent or intellectual person
(2) : the chief planner within a group usually used in pluralshe'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

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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.
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Recent Examples on the Web: Noun Former President Jimmy Carter was admitted to a Georgia hospital Monday and is scheduled to undergo a procedure to relieve pressure on his brain caused by bleeding from recent falls, The Carter Center said. Phil Helsel, NBC News, "President Jimmy Carter to undergo procedure to relieve pressure on brain from falls," 12 Nov. 2019 Former President Jimmy Carter has been hospitalized for a procedure to reduce pressure on his brain. Fox News, "President Jimmy Carter hospitalized for procedure to reduce pressure on brain after recent falls," 12 Nov. 2019 Former President Jimmy Carter is reportedly recovering after surgery this morning to relieve pressure on his brain. Essence, "President Jimmy Carter Recovering From Surgery To Relieve Pressure From Brain," 12 Nov. 2019 But Prather says all phases, from the lightest slumber to the deepest unconsciousness, are important processes that allow our brains and bodies to recover from the previous day and can help us learn and remember information better. Wired, "The Science Is Extremely Clear: You Need to Prioritize Sleep," 12 Nov. 2019 There is pleasure in sameness, since music itself triggers pleasure areas in our brains. Caroline Delbert, Popular Mechanics, "The Enduring Appeal of 'I Will Always Love You,' Explained by Science," 11 Nov. 2019 The medical examiner determined the baby’s cause of death was acute and chronic blunt injuries with brain hemorrhages and rib fractures and determined the manner of death to be homicide. David Owens, courant.com, "Hartford mother charged in infant daughter’s death pleads guilty, agrees to testify against child’s father," 8 Nov. 2019 Former President Jimmy Carter, after doctors told him in 2015 that cancer had spread to his brain. Michelle Krupa, CNN, "5 things to know for November 4: Impeachment, McDonald's, Airbnb, measles," 4 Nov. 2019 Alexandra Munroe, the senior curator of Asian art at the Guggenheim Museum in New York, said the cause was a brain hemorrhage. New York Times, "Huang Yong Ping, 65, Dies; His Art Saw a World of Power Struggles," 29 Oct. 2019 Recent Examples on the Web: Verb The yawning space between is echoed by an endless lateral runway that makes every entrance and exit seem like a trek and requires the actors to duck their heads to avoid getting brained on the way out. David Rooney, The Hollywood Reporter, "'The Rose Tattoo': Theater Review," 16 Oct. 2019 Yet focusing on chicken shops is not completely bird-brained. The Economist, "A British anti-knife drive comes home to roost," 22 Aug. 2019 In many cases, this appears tied to brain abnormalities…. There are different terms and models for assessing such a person. James Fallows, The Atlantic, "On Trump and Queeg: A Followup," 25 Aug. 2019 Long before blows land, the audience is taking inventory of the props, assessing which could be used by one brother to brain or strangle the other. Graeme Wood, The Atlantic, "Sam Shepard Saw It All Coming," 11 July 2019 These structures also raise an ethical question that used to be strictly in the realm of science fiction — can brain organoids become sufficiently advanced to develop consciousness? San Diego Union-Tribune, "Biotech notebook: Cancer discovery, bacterial syringes and organoids," 13 July 2019 By the 1980s, scientists had figured out that our early ancient relatives were short and small-brained up to about two million years ago. Quanta Magazine, "Scientists Seek to Update Evolution," 22 Nov. 2016 And yet the story rolls on, oblivious and hare-brained. John Anderson, WSJ, "‘The Romanoffs’ Review: Far From Revolutionary," 11 Oct. 2018 According to the study, the ratio of neurons to brain size in most carnivores was nearly equivalent to herbivores. Elly Belle, Teen Vogue, "Study Says Dogs Are Actually Smarter Than Cats," 18 June 2018

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.

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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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Statistics for brain

Last Updated

16 Nov 2019

Cite this Entry

“Brain.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/braining. Accessed 22 November 2019.

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More Definitions for brain

brain

noun
How to pronounce brain (audio)

English Language Learners Definition of brain

 (Entry 1 of 2)

: the organ of the body in the head that controls functions, movements, sensations, and thoughts
informal : the ability to think and reason
informal : a very intelligent person

brain

verb

English Language Learners Definition of brain (Entry 2 of 2)

informal : to hit (someone) on the head very hard

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

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More from Merriam-Webster on brain

Thesaurus: All synonyms and antonyms for brain

Rhyming Dictionary: Words that rhyme with brain

Spanish Central: Translation of 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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