brain definition | Dictionary.com

Synonyms of brain

mind, brainpower, intellect, mentality, sense, understanding, wit, intellectual, thinker, brainy, cerebral, clever

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10 dictionary results for: brain

Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This

brain

[breyn] Pronunciation Key

–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.

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.

Informal.

a.	the controlling or guiding mechanism in a computer, robot, pacemaker, etc.

b.	the part of a computer system for coordination or guidance, as of a missile.

–verb (used with object)

8.	to smash the skull of.

9.	Slang. to hit or bang (someone) on the head.

—Idioms

10.	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.

11.	have something on the brain, to have an obsession; be occupied with: Lately I seem to have food on the brain.

12.	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.

[Origin: bef. 1000; ME; OE bræg(e)n, bregen; c. LG brägen, D brein

]

—Related forms

brainlike, adjective

—Synonyms 3. sense; capacity. See mind.

Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.

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American Heritage Dictionary - Cite This Source - Share This

brain (brān) Pronunciation Key

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n.

1. The portion of the vertebrate central nervous system that is enclosed within the cranium, continuous with the spinal cord, and composed of gray matter and white matter. It is the primary center for the regulation and control of bodily activities, receiving and interpreting sensory impulses, and transmitting information to the muscles and body organs. It is also the seat of consciousness, thought, memory, and emotion.
2. A functionally similar portion of the invertebrate nervous system.
3. Intellectual ability; mind: a dull brain; a quick brain.
4. Intellectual power; intelligence. Often used in the plural: has brains and good looks. See Synonyms at mind.
1. Intellectual ability; mind: a dull brain; a quick brain.
2. Intellectual power; intelligence. Often used in the plural: has brains and good looks. See Synonyms at mind.
A highly intelligent person.
The primary director or planner, as of an organization or movement. Often used in the plural.
The control center, as of a ship, aircraft, or spacecraft.

tr.v. brained, brain·ing, brains Slang

To smash in the skull of.
To hit on the head.

[Middle English, from Old English brægen.]

(Download Now or Buy the Book)
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

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Online Etymology Dictionary - Cite This Source - Share This
brain

O.E. brægen, from P.Gmc. *bragnam, from PIE base *mregh-m(n)o- "skull, brain" (cf. Gk. brekhmos "front part of the skull"). The custom of using the plural to refer to the substance (literal or figurative), as opposed to the organ, dates from 16c. Fig. sense of "intellectual power" is from 1393; meaning "a clever person" is first recorded 1914. Brainstorm "brilliant idea, mental excitement" is 1849; verb is from 1920s; brainsick (1483) meant "mad, addled." Brain-dead is from 1976; brain teaser is from 1923. Brainwashing is 1950, a literal translation of Chinese xi nao. Though it had been occasionally used since early 1900s, brain trust became current 1933, in ref. to the intellectuals gathered by U.S. President Franklin D. Roosevelt as advisors.

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WordNet - Cite This Source - Share This

brain
noun
1.	that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
2.	mental ability; "he's got plenty of brains but no common sense"
3.	that which is responsible for one's thoughts and feelings; the seat of the faculty of reason; "his mind wandered"; "I couldn't get his words out of my head" [syn: mind]
4.	someone who has exceptional intellectual ability and originality; "Mozart was a child genius"; "he's smart but he's no Einstein" [syn: genius]
5.	the brain of certain animals used as meat
verb
1.	hit on the head
2.	kill by smashing someone's skull

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American Heritage Dictionary of Idioms - Cite This Source - Share This

brain

In addition to the idioms beginning with brain, also see beat one's brains out; blow one's brains out; on one's mind (the brain); pick someone's brains; rack one's brains.

The American Heritage® Dictionary of Idioms by Christine Ammer.
Copyright © 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Company.

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The American Heritage Science Dictionary - Cite This Source - Share This

brain (brān) Pronunciation Key

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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. See more at brainstem , cerebellum , cerebrum.
A bundle of nerves in many invertebrate animals that is similar to the vertebrate brain in function and position.

The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

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American Heritage New Dictionary of Cultural Literacy, Third Edition - Cite This Source - Share This
brain

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.

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American Heritage Stedman's Medical Dictionary - Cite This Source - Share This

brain (brān)
n.
The portion of the central nervous system that is enclosed within the cranium, continuous with the spinal cord, and composed of gray matter and white matter. It is the primary center for the regulation and control of bodily activities, receiving and interpreting sensory impulses, and transmitting information to the muscles and body organs. It is also the seat of consciousness, thought, memory, and emotion. Also called encephalon.

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Webster's Revised Unabridged Dictionary - Cite This Source - Share This

Brain

Brain\, n. [OE. brain, brein, AS. bragen, br[ae]gen; akin to LG. br["a]gen, bregen, D. brein, and perh. to Gr. ?, the upper part of head, if ? =?. [root]95.]

1. (Anat.) The whitish mass of soft matter (the center of the nervous system, and the seat of consciousness and volition) which is inclosed in the cartilaginous or bony cranium of vertebrate animals. It is simply the anterior termination of the spinal cord, and is developed from three embryonic vesicles, whose cavities are connected with the central canal of the cord; the cavities of the vesicles become the central cavities, or ventricles, and the walls thicken unequally and become the three segments, the fore-, mid-, and hind-brain.

Note: In the brain of man the cerebral lobes, or largest part of the forebrain, are enormously developed so as to overhang the cerebellum, the great lobe of the hindbrain, and completely cover the lobes of the midbrain. The surface of the cerebrum is divided into irregular ridges, or convolutions, separated by grooves (the so-called fissures and sulci), and the two hemispheres are connected at the bottom of the longitudinal fissure by a great transverse band of nervous matter, the corpus callosum, while the two halves of the cerebellum are connected on the under side of the brain by the bridge, or pons Varolii.

2. (Zo["o]l.) The anterior or cephalic ganglion in insects and other invertebrates.

3. The organ or seat of intellect; hence, the understanding. " My brain is too dull." --Sir W. Scott.

Note: In this sense, often used in the plural.

4. The affections; fancy; imagination. [R.] --Shak.

To have on the brain, to have constantly in one's thoughts, as a sort of monomania. [Low]

Brain box or case, the bony on cartilaginous case inclosing the brain.

Brain coral, Brain stone coral (Zo["o]l), a massive reef-building coral having the surface covered by ridges separated by furrows so as to resemble somewhat the surface of the brain, esp. such corals of the genera M[ae]andrina and Diploria.

Brain fag (Med.), brain weariness. See Cerebropathy.

Brain fever (Med.), fever in which the brain is specially affected; any acute cerebral affection attended by fever.

Brain sand, calcareous matter found in the pineal gland.

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Webster's Revised Unabridged Dictionary - Cite This Source - Share This

Brain

Brain\, v. t. [imp. & p. p. Brained; p. pr. & vb. n. Braining.]

1. To dash out the brains of; to kill by beating out the brains. Hence, Fig.: To destroy; to put an end to; to defeat.

There thou mayst brain him. --Shak.

It was the swift celerity of the death . . . That brained my purpose. --Shak.

2. To conceive; to understand. [Obs.]

?T is still a dream, or else such stuff as madmen Tongue, and brain not. --Shak.