Fissure

[fish-er] /ˈfɪʃ ər/

noun
1.
a narrow opening produced by or separation of parts.
2.
(def 1).
3.
Anatomy. a natural division or groove in an organ, as in the brain.
verb (used with object), fissured, fissuring.
4.
to make fissures in; cleave; split.
verb (used without object), fissured, fissuring.
5.
to open in fissures; become split.
/ˈfɪʃə/
noun
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) a narrow split or groove that divides an organ such as the brain, lung, or liver into lobes See also sulcus
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
verb
6.
to crack or split apart
n.

c.1400, from Old French fissure (13c.) and directly from Latin fissura “a cleft,” from root of findere “to split, cleave,” from PIE *bhi-n-d-, from root *bheid- “to split” (cf. Sanskrit bhinadmi “I cleave,” Old High German bizzan “to bite,” Old English bita “a piece bitten off, morsel,” Old Norse beita “to hunt with dogs,” beita “pasture, food”).

fissure fis·sure (fĭsh’ər)
n.

fissure
(fĭsh’ər)
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.