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-.]
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