Anatomy, Zoologythe mass of nerve tissue in the head of humans and animals that is the center of the nervous system.
Sometimes, brains. understanding; intellectual power; intelligence:He has a good brain for math. She sometimes acts as if she has no brains.
Slang Termsbrains,Slang.[the + ~; used with a singular verb] a member of a group who is regarded as having the intelligence necessary to lead:Who was the brains behind this evil plot?
Informal TermsInformal. an extremely intelligent person:She's a real brain in chemistry.
v.[~ + object]
Slang TermsSlang. to hit or bang on the head:What are you doing, braining your little brother?
Idioms
Informal Terms, Idiomsbeat or rack one's brains (out), [no object]Informal. to try very hard to work out a problem, remember something, etc.:beat her brains out trying to come up with a fair solution.
beat someone's brains out, [no object] to injure by hitting or beating very hard, as by hitting on the head:She leaped on top of him and beat his brains out.
Idiomspick someone's brains, to obtain information by questioning another person:didn't prepare for the exam but counted on picking his roommate's brains.
Anatomy, Zoologythe 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.
Zoology(in many invertebrates) a part of the nervous system more or less corresponding to the brain of vertebrates.
Sometimes, brains. (used with a pl. v.) understanding; intellectual power; intelligence.
the brain as the center of thought, understanding, etc.; mind; intellect.
Slang Termsbrains, a member of a group who is regarded as its intellectual leader or planner:The junior partner is the brains of the firm.
Informal Termsa very intelligent or brilliant person.
Computing, Informal Terms[Informal.]
the controlling or guiding mechanism in a computer, robot, pacemaker, etc.
the part of a computer system for coordination or guidance, as of a missile.
Informal Termsbeat one's brains out, to try very hard to understand and work out a problem, remember something, etc.:She beat her brains out studying for the exam.
Idiomshave something on the brain, to have an obsession; be occupied with:Lately I seem to have food on the brain.
Idiomspick 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.
v.t.
to smash the skull of.
Slang Termsto hit or bang (someone) on the head.
bef. 1000; Middle English; Old English bræg(e)n, bregen; cognate with Low German brägen, Dutch brein
brain′like′, adj.
3.See corresponding entry in Unabridged sense; capacity. See mind.
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