brain Meaning, Definition & Usage

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

WordNet

Brain noun
Etymology
OE. brain, brein, AS. bragen, brægen; akin to LG. brägen, bregen, D. brein, and perh. to Gr. , the upper part of head, if = 95.
Definitions
  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. ✍ 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. (Zoöl.) 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. ✍ In this sense, often used in the plural.
  4. The affections; fancy; imagination. R. Shak.
Brain transitive verb
Wordforms
imperfect & past participle Brained present participle & verbal noun Braining
Definitions
  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.

Webster 1913