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 Eventually, Malick is able to go deep enough into Simmons’ brain to see memories of her, Fitz, and Enoch working out their plan. Christian Holub, EW.com, "Agents of S.H.I.E.L.D. recap: The end is near," 6 Aug. 2020 Damron was released from Eskenazi the following day, having sustained brain bleeding and a fracture to his skull. Holly V. Hays, The Indianapolis Star, "'I'm grateful': Man meets medics, firefighters who pulled him from Memorial Day crash," 6 Aug. 2020 This rapid decline suggests that intonation is processed in the more ancient dog brain regions. Virginia Morell, National Geographic, "Dogs understand praise the same way we do. Here's why that matters.," 6 Aug. 2020 So focus shifted to the relative sizes of brain regions. Ari Berkowitz, The Conversation, "Brain scientists haven’t been able to find major differences between women’s and men’s brains, despite over a century of searching," 6 Aug. 2020 Not only do the Staffords have four girls under the age of 4, including a 1-month-old, but Kelly's has had her own major health battle after having brain surgery last year to have a tumor removed. Kirkland Crawford, Detroit Free Press, "Kelly Stafford describes COVID-19 scare involving husband Matthew, rips NFL," 4 Aug. 2020 Many of Lapointe’s health problems were effects of Dandy Walker syndrome, a hereditary condition that causes abnormal brain development and can inhibit coordination, speech, memory and abstract thinking. Edmund H. Mahony, courant.com, "Coronavirus claims Richard Lapointe, who survived a quarter century in prison following a wrongful murder conviction," 4 Aug. 2020 Grace comes to the table with a plate of food for her, which turns out to be a brain. Rachel Paige, refinery29.com, "R29 Binge Club: Umbrella Academy Season 2 Recap," 3 Aug. 2020 Nearly all dementia patients have other brain abnormalities, including blood vessel damage likely to be the result of high blood pressure. Gina Kolata, New York Times, "Dementia on the Retreat in the U.S. and Europe," 3 Aug. 2020 Recent Examples on the Web: Verb To Rio’s distress, a group of boys at a table nearby start to flirt coarsely with the overdeveloped and somewhat under-brained Pucha. Deborah Eisenberg, The New York Review of Books, "Tyrannical Days," 27 May 2020 The people who can make an outsized difference bring a combination of what is conventionally known as left-brained and right-brained thinking. Quartz India, "Kunal Shah on the jobs that will define India’s future," 11 Feb. 2020 This has meant keeping the games going even as the league faced everything from domestic abuse cases to brain injuries. Jason Parham, WIRED, "Depth of Field: Where Is Jay-Z Taking the NFL?," 15 Aug. 2019 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

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

9 Aug 2020

Cite this Entry

“Brain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brain. Accessed 11 Aug. 2020.

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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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