1. A long narrow opening; a crack or cleft.
2. The process of splitting or separating; division.
3. A separation into subgroups or factions; a schism.
4. Anatomy A normal groove or furrow, as in the liver or brain, that divides an organ into lobes or parts.
5. Medicine A break in the skin, usually where it joins a mucous membrane, producing a cracklike sore or ulcer.
intr. & tr.v. fis·sured, fis·sur·ing, fis·sures
To form a crack or cleft or cause a crack or cleft in.
[Middle English, cut, from Old French, from Latin fissūra, from fissus, split; see FISSI-.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.