Definition of "fissure" []

• 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. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "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 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."
• "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."