A model of the human brain.
- The definition of a brain is the mass of nerve tissue located in the head of animals with spinal cords; it is the center of thought and controls movement.
An example of brain is what is damaged when someone has Alzheimer's disease.
- A brain is defined as a smart or intellectual person.
An example of brain is a student who is valedictorian of their class.
- [sometimes pl.] the mass of nerve tissue in the cranium of vertebrate animals, an enlarged extension of the spinal cord: it is the main part of the nervous system, the center of thought, and the organ that perceives sensory impulses and regulates motor impulses: it is made up of gray matter (the outer cortex of nerve cells) and white matter (the inner mass of nerve fibers)
- a comparable organ in invertebrate animals
- [often pl.] intelligence; mental ability
- Informal a person of great intelligence
- [usually pl.]Informal the main organizer or planner of a group activity; chief controller or director
Origin of brainMiddle English from Old English brægen from Indo-European base an unverified form mregh-m(n)o-, skull, brain from source Classical Greek bregma, forehead
- to dash out the brains of
- Slang to hit hard on the head
have on the brain
pick someone's brains
- a. 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.b. A functionally similar portion of the invertebrate nervous system.
- a. Intellectual ability; intellect: an actor not known for his quick brain.b. often brains Exceptional intellectual ability; intelligence: has brains and good looks.c. Informal A highly intelligent person: We knew the new kid was a brain as soon as she started talking.
- often brains The primary director or planner, as of an organization or movement.
- The control center, as of a ship, aircraft, or spacecraft.
transitive verbbrained, brain·ing, brains
Origin of brainMiddle English from Old English brægen
the human brain and its contiguous structures
A. pituitary gland
D. corpus callosum
J. spinal cord
- The control center of the central nervous system of an animal located in the skull which is responsible for perception, cognition, attention, memory, emotion, and action.
- (informal) An intelligent person.
- He was a total brain.
- (UK, plural only) A person who provides the intelligence required for something.
- He is the brains behind the scheme.
- (in the plural) Intellect.
- He has a lot of brains.
- By analogy with a human brain, the part of a machine or computer that performs calculations.
- The computer's brain is capable of millions of calculations a second.
(third-person singular simple present brains, present participle braining, simple past and past participle brained)
From Middle English brain, from Old English bræġen (“brain”), from Proto-Germanic *bragną (“brain”), from Proto-Indo-European *mreghmno-, *mreghmo- (“skull, brain”), from Proto-Indo-European *mreK- (“marrow, sinciput”). Cognate with Scots braine, brane (“brain”), North Frisian brayen, brein (“brain”), West Frisian brein (“brain”), Dutch brein (“brain”), Low German Brägen (“brain”), Bregen Ancient Greek βρεχμός (brechmos, “front part of the skull, top of the head”).