brain
brain definition
brain (brān)
noun
- 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
- intelligence; mental ability
- Informal a person of great intelligence
- Informal the main organizer or planner of a group activity; chief controller or director
Etymology: ME < OE brægen < IE base *mregh-m(n)o-, skull, brain > Gr bregma, forehead
transitive verb
- to dash out the brains of
- Slang to hit hard on the head
brain Idioms
beat one's brains
or rack one's brains or cudgel one's brains to try hard to remember, understand, or solve something
have on the brain
to be obsessed by
pick someone's brains
to extract information, ideas, etc. from someone and use to one's own advantage
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