FISSURE 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…