from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A long narrow opening; a crack or cleft.
  • noun The process of splitting or separating; division.
  • noun A separation into subgroups or factions; a schism.
  • noun Anatomy A normal groove or furrow, as in the liver or brain, that divides an organ into lobes or parts.
  • noun Medicine A break in the skin, usually where it joins a mucous membrane, producing a cracklike sore or ulcer.
  • intransitive & transitive verb To form a crack or cleft or cause a crack or cleft in.

from The Century Dictionary.

  • To cleave; split; divide; crack or fracture.
  • To crack; cleave; split open.
  • noun A longitudinal depression on the under surface of the liver.
  • noun A narrow longitudinal opening or groove; a cleft, crack, or chink; a line of separation in any substance produced by parting or cleavage: as, a fissure in the earth or in a rock.
  • noun In surgery and anatomy, any solution of continuity in a bone, membrane, or muscle, or a natural division or groove between adjoining parts of like substance; a fissura: a sulcus: as, the longitudinal fissure of the brain, separating the hemispheres.
  • noun In entomology: A deep, sharp longitudinal depression of a surface.
  • noun A very deep angular notch in a margin, almost dividing the part or organ.
  • noun In botany, the opening between segments of a cleft leaf or other organ; a slit formed by the dehiscence of an anther or a capsule.
  • noun In heraldry, a bearing resembling the bend sinister, but having one fourth the width of the bend, and capable of being borne on any part of the shield, sometimes in connection with others, sometimes with a bend sinister, a scarpe, or the like. Also called staff.
  • noun In pathology, a crack-like sore or ulcer: as, an anal fissure.
  • noun See the adjectives.

from the GNU version of the Collaborative International Dictionary of English.

  • transitive verb To cleave; to divide; to crack or fracture.
  • noun A narrow opening, made by the parting of any substance; a cleft.
  • noun (Anat.) the furrows or clefts by which the surface of the cerebrum is divided; esp., the furrows first formed by the infolding of the whole wall of the cerebrum.
  • noun (Surg.) a spiral needle for catching together the gaping lips of wounds.
  • noun (Anat.) the furrow separating the frontal from the parietal lobe in the cerebrum.
  • noun (Anat.) a deep cerebral fissure separating the frontal from the temporal lobe. See Illust. under Brain.
  • noun (Mining) a crack in the earth's surface filled with mineral matter.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun a crack or opening, as in a rock
  • verb To split forming fissures.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a long narrow opening
  • noun a long narrow depression in a surface
  • verb break into fissures or fine cracks
  • noun (anatomy) a long narrow slit or groove that divides an organ into lobes


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, cut, from Old French, from Latin fissūra, from fissus, split; see fissi–.]


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  • The spinal cord is divided in front through the middle nearly as far as its center, by a deep fissure, called the _anterior fissure_, and behind, in a similar manner, by the posterior _fissure_.

    The People's Common Sense Medical Adviser in Plain English or, Medicine Simplified, 54th ed., One Million, Six Hundred and Fifty Thousand Ray Vaughn Pierce 1877

  • The term fissure is applied to such grooves as involve the entire thickness of the cerebral wall, and thus produce corresponding eminences in the ventricular cavity, while the sulci affect only the superficial part of the wall, and therefore leave no impressions in the ventricle.

    IX. Neurology. 2. Development of the Nervous System 1918

  • A noxious, sulfuric smell that says that this fissure is a vent for the same gases that make the hot springs so warm and bubbly.

    Boing Boing: September 24, 2006 - September 30, 2006 Archives 2006

  • It is sometimes called the fissure of Rolando, after an 18th-century Italian anatomist, Luigi Rolando, who was the first to describe it carefully.

    The Human Brain Asimov, Isaac 1963

  • This circumstance is considered by the Uzbeks as a miracle, and attributed by them to the son of David; but the more natural explanation would be, that a considerable fissure from the bed of the Oxus, which, from a point at a greater elevation, finds its exit here, and in the lapse of ages having discharged its stream of water impregnated with fine sand, has given rise to the monticule as it now appears, and whose dimensions will probably still increase.

    Glimpses of Life and Manners in Persia 1856

  • The results can only be credibly attributed to the influence of such strategic choice if the fissure is a hidden one, because once the fissure has already surfaced it is just a matter of time rather than the result of your action/inaction.

    Archive 2006-07-01 Sun Bin 2006

  • The results can only be credibly attributed to the influence of such strategic choice if the fissure is a hidden one, because once the fissure has already surfaced it is just a matter of time rather than the result of your action/inaction.

    Guo Jia (iii) - Three-way statecraft around the Sea of Japan (aks East Sea) Sun Bin 2006

  • The sunlight showed, too, that the fissure was the skylight of a cave which opened out on the ravine.

    Tropic Days 2003

  • Referring again to the search for the crack, it is well to know that with toe-crack the fissure is the more readily seen when the foot is lifted from the ground.

    Diseases of the Horse's Foot Harry Caulton Reeks

  • We did so, but it appeared that the spot at which we originally struck the fissure was the narrowest place; it widened at either side.

    Chatterbox, 1905. Various


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