brain

[ breyn ]

noun

1. Anatomy, Zoology. the part of the central nervous system enclosed in the cranium of humans and other vertebrates, consisting of a soft, convoluted mass of gray and white matter and serving to control and coordinate the mental and physical actions.
2. Zoology. (in many invertebrates) a part of the nervous system more or less corresponding to the brain of vertebrates.
3. Sometimes brains. (used with a plural verb) understanding; intellectual power; intelligence.

   Synonyms: capacity, sense

4. the brain as the center of thought, understanding, etc.; mind; intellect.
5. brains, Slang. a member of a group who is regarded as its intellectual leader or planner:

   The junior partner is the brains of the firm.

6. Informal. a very intelligent or brilliant person.
7. Informal.
   1. the controlling or guiding mechanism in a computer, robot, pacemaker, etc.
   2. the part of a computer system for coordination or guidance, as of a missile.

verb (used with object)

1. to smash the skull of.
2. Slang. to hit or bang (someone) on the head.

brain

/ breɪn /

noun

1. the soft convoluted mass of nervous tissue within the skull of vertebrates that is the controlling and coordinating centre of the nervous system and the seat of thought, memory, and emotion. It includes the cerebrum, brainstem, and cerebellum Technical nameencephalon cerebralencephalic
2. the main neural bundle or ganglion of certain invertebrates
3. informal.
   often plural intellectual ability

   he's got brains

4. informal.
   shrewdness or cunning
5. informal.
   an intellectual or intelligent person
6. informal.
   usually plural; functioning as singular a person who plans and organizes an undertaking or is in overall control of an organization, etc
7. an electronic device, such as a computer, that performs apparently similar functions to the human brain
8. on the brain
   constantly in mind

   I had that song on the brain

9. pick someone's brain
   to obtain information or ideas from someone

verb

1. to smash the skull of
2. slang.
   to hit hard on the head

brain

/ brān /

1. The part of the nervous system in vertebrates that is enclosed within the skull, is connected with the spinal cord, and is composed of gray matter and white matter. It is the control center of the central nervous system, receiving sensory impulses from the rest of the body and transmitting motor impulses for the regulation of voluntary movement. The brain also contains the centers of consciousness, thought, language, memory, and emotion.
2. See more at brainstem
3. A bundle of nerves in many invertebrate animals that is similar to the vertebrate brain in function and position.

brain

1. The central organ in the nervous system , protected by the skull. The brain consists of the medulla , which sends signals from the spinal cord to the rest of the brain and also controls the autonomic nervous system ; the pons , a mass of nerve fibers connected to the medulla; the cerebellum , which controls balance and coordination; and the cerebrum , the outer layer of which, the cerebral cortex , is the location of memory, sight, speech, and other higher functions. The cerebrum contains two hemispheres (the left hemisphere and the right hemisphere), each of which controls different functions. In general, the right hemisphere controls the left side of the body and such functions as spatial perception, whereas the left hemisphere controls the right side of the body and functions such as speech. Under the cerebral cortex are the thalamus , the main relay center between the medulla and the cerebrum; and the hypothalamus , which controls blood pressure , body temperature, hunger, thirst, sex drive, and other visceral functions.

Other Words From

• brainlike adjective
• super·brain noun

Word History and Origins

Origin of brain¹

First recorded before 1000; Middle English; Old English bræg(e)n, bregen; cognate with Low German brägen, Dutch brein; akin to Greek brégma; bregma ( def )

Word History and Origins

Origin of brain¹

Old English brægen ; related to Old Frisian brein , Middle Low German bregen , Greek brekhmos forehead

Idioms and Phrases

Idioms

1. beat one's brains out, Informal. to try very hard to understand and work out a problem, remember something, etc.:

   She beat her brains out studying for the exam.

2. have something on the brain, to have an obsession; be occupied with:

   Lately I seem to have food on the brain.

3. pick someone's brains, to obtain information by questioning another person rather than by seeking it independently:

   He refused to prepare for the exam but counted on being able to pick his roommate's brains.

More idioms and phrases containing brain

• beat one's brains out
• blow one's brains out
• on one's mind (the brain)
• pick someone's brains
• rack one's brains

Synonym Study

See mind.

Example Sentences

One possible explanation is that these drugs increase the risk of microbleeds in the brain, which are associated with cognitive decline.

From Science Daily

The second miracle attributed to Mr Acutis came in 2024, when a university student in Florence was healed despite having bleeding on the brain after suffering head trauma.

From BBC

This happens everywhere except for the very top of the skull to give the brain space to grow.

From BBC

This was in marked contrast to the main clock in the brain, plus feelings of sleepiness and alertness, which had not recovered within 5 days of the 5-hour time delay.

From Science Daily

Although the underlying mechanisms are not fully understood, scientists think that some of the hallmarks of diabetes -- such as high blood sugar, insulin resistance, and inflammation -- may encourage the development of dementia in the brain.

From Science Daily

Related Words

• head
• intellect
• mind

More About Brain

What is a basic definition of brain?

The brain is the organ in humans and animals that’s responsible for thought processes. The plural form brains refers to intelligence or a person who is the smartest member of a group. The word brain has several other senses as a noun and a few as a verb.

Your brain is a squishy organ located inside your head and is protected by your skull. The brain is highly complex. It is the seat of all your conscious thoughts and unconscious impulses and is like the control center of the body, allowing you to do things like speak, move your muscles, and breathe without thinking. The brain, spinal cord, and nerves make up the nervous system.

Real-life examples: You and every other person have a brain. Animals have brains too, although they aren’t capable of doing all of the things the human brain is able to do. Your brain is very important and has a vast number of jobs, such as keeping all of your memories, telling your other organs what to do, and helping you read these words.

Used in a sentence The brain is the most complex and perhaps the most studied organ.  

The plural form brains is used as a term for intelligence or intellect. This usage alludes to the brain being the organ that handles thinking.

Real-life examples: You may have heard a person being described as having brains. This means they are smart and able to figure things out, especially difficult or complex problems.

Used in a sentence: I have to study hard to do well in math, but my sister has brains and aces her tests without studying. 

Relatedly, a person who is considered very smart can be called a brain.

Used in a sentence: None of us could figure out the computer problem so we called in Mike, who was a real brain when it comes to fixing them. 

Brains is also used to refer to the smartest member or members of a group or team, especially the one who comes up with plans.

Real-life examples: Movies and shows that feature a heist or a plan often have a person who is referred to as the “brains of the operation.” For example, scientist Bruce Banner often comes up with plans or solutions for the Avengers (when he isn’t getting angry and turning into the Incredible Hulk). In the Harry Potter series, Hermione is definitely the brains of the trio that she forms with Harry and Ron.

Used in a sentence: Everyone knew that Edd was the real brains behind the money-making schemes.

Where does brain come from?

The first records of brain come from before the year 1000. It comes from the Old English brægen (“brain”). This term is related to other words for brain, such as the Old Frisian brein, the Middle Low German brēgen, and Greek brekhmos (“forehead”).

Did you know ... ?

What are some other forms related to brain?

• brainlike (adjective)
• superbrain (noun)

What are some synonyms for brains?

• intelligence
• intellect
• smarts

What are some words that share a root or word element with brain? 

• brainy
• brainstorm
• brain freeze
• brainiac
• braindead

What are some words that often get used in discussing brain?

• nervous system
• thought
• use
• hurts

How is brain used in real life?

Brain is a common word that refers to either the organ in your skull or your intellect.

I wonder what the part of my brain that used to remember phone numbers is up to these days ☺️

— RiCKY🇿🇼🇿🇼🇿🇼 (@ricardothezimbo) November 22, 2020

If I need to be the brains of the operation, we're in big trouble.

— Captain Connecticut (@byronblurb) December 30, 2012

did anyone else get lost at the end of The Witcher? I legit don't have the brains for it

— dakotaz (@dakotaz) January 7, 2020

 

 

Try using brain!

True or False?

Someone who is described as having brains is usually someone who is very smart.