Brain n.
 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.
 Note: ☞ 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. Zool. The anterior or cephalic ganglion in insects and other invertebrates.
 3. The organ or seat of intellect; hence, the understanding; as, use your brains. “ My brain is too dull.”
 Note: ☞ In this sense, often used in the plural.
 4. The affections; fancy; imagination. [R.]
 To have on the brain, to have constantly in one's thoughts, as a sort of monomania. [Low]
 no-brainer a decision requiring little or no thought; an obvious choice. [slang]
 Brain box or  Brain case, the bony or cartilaginous case inclosing the brain.
 Brain coral, Brain stone coral Zool., a massive reef-building coral having the surface covered by ridges separated by furrows so as to resemble somewhat the surface of the brain, esp. such corals of the genera Mæandrina and Diploria.
 Brain fag Med., brain weariness. See Cerebropathy.
 Brain fever Med., fever in which the brain is specially affected; any acute cerebral affection attended by fever.
 Brain sand, calcareous matter found in the pineal gland.


 Fe·ver n.
 1. Med. A diseased state of the system, marked by increased heat, acceleration of the pulse, and a general derangement of the functions, including usually, thirst and loss of appetite.  Many diseases, of which fever is the most prominent symptom, are denominated fevers; as, typhoid fever; yellow fever.
 Note: ☞ Remitting fevers subside or abate at intervals; intermitting fevers intermit or entirely cease at intervals; continued or continual fevers neither remit nor intermit.
 2. Excessive excitement of the passions in consequence of strong emotion; a condition of great excitement; as, this quarrel has set my blood in a fever.
 An envious fever
 Of pale and bloodless emulation.   --Shak.
    After life's fitful fever he sleeps well.   --Shak.
 Brain fever, Continued fever, etc. See under Brain, Continued, etc.
 Fever and ague, a form of fever recurring in paroxysms which are preceded by chills. It is of malarial origin.
 Fever blister Med., a blister or vesicle often found about the mouth in febrile states; a variety of herpes.
 Fever bush Bot., the wild allspice or spice bush. See Spicewood.
 Fever powder. Same as Jame's powder.
 Fever root Bot., an American herb of the genus Triosteum (Triosteum perfoliatum); -- called also feverwort and horse gentian.
 Fever sore, a carious ulcer or necrosis. --Miner.


 brain fever
      n : meningitis caused by bacteria and often fatal [syn: {cerebrospinal
          meningitis, epidemic meningitis, cerebrospinal fever]