Fis·sure n. A narrow opening, made by the parting of any substance; a cleft; as, the fissure of a rock.
Cerebral fissures 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.
Fissure needle Surg., a spiral needle for catching together the gaping lips of wounds. --Knight.
Fissure of rolando Anat., the furrow separating the frontal from the parietal lobe in the cerebrum.
Fissure of Sylvius Anat., a deep cerebral fissure separating the frontal from the temporal lobe. See Illust. under Brain.
Fissure vein Mining, a crack in the earth's surface filled with mineral matter. --Raymond.