brain
(brān)
(brān)n.
1.
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.
2.
a. Intellectual ability; intellect:an actor not known for his quick brain.
b. oftenbrainsExceptional 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.
3. oftenbrainsThe primary director or planner, as of an organization or movement.
4. The control center, as of a ship, aircraft, or spacecraft.
tr.v.brained, brain·ing, brains
Idioms: To hit on the head or kill by hitting on the head.
beat (one's) brains (out)
Informal To exert or expend great mental effort:She beat her brains out during the examination.
on the brain
Obsessively in mind:The coach has winning on the brain.
pick (someone's)brain/brains
To explore another's ideas through questioning.
rack (one's) brainInformal
To think long and hard:I racked my brain for hours trying to recall her name.
[Middle English, fromOld Englishbrægen.]
brainthe human brain and its contiguous structures
A. pituitary gland
B. cerebrum
C. skull
D. corpus callosum
E. thalamus
F. hypothalamus
G. pons
H. cerebellum
I. medulla
J. spinal cord