|1.||any long narrow cleft or crack, esp in a rock|
|2.||a weakness or flaw indicating impending disruption or discord: fissures in a decaying empire|
|3.||anatomy See also sulcus a narrow split or groove that divides an organ such as the brain, lung, or liver into lobes|
|4.||a small unnatural crack in the skin or mucous membrane, as between the toes or at the anus|
|5.||a minute crack in the surface of a tooth, caused by imperfect joining of enamel during development|
|6.||to crack or split apart|
|[C14: from medical Latin fissūra, from Latin fissus split]|
fissure fis·sure (fĭsh'ər)
A deep furrow, cleft, or slit.
A developmental break or fault in the enamel of a tooth.
|fissure (fĭsh'ər) Pronunciation Key
A long, narrow crack or opening in the face of a rock. Fissures are often filled with minerals of a different type from those in the surrounding rock.