a narrow opening produced by cleavage or separation of parts.
Anatomy. a natural division or groove in an organ, as in the brain.

verb (used with object), fis·sured, fis·sur·ing.

to make fissures in; cleave; split.

verb (used without object), fis·sured, fis·sur·ing.

to open in fissures; become split.

Origin of fissure

1375–1425; late Middle English < Latin fissūra cleaving, cleft, fissure, equivalent to fiss(us) divided (see fissi-) + -ūra -ure
Related formsfis·su·ral, adjectivefis·sure·less, adjectivesub·fis·sure, nounsu·per·fis·sure, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for fissure

crevice, cleavage, cleft, hole, crack

Examples from the Web for fissure

Contemporary Examples of fissure

Historical Examples of fissure

  • The least fissure in the latter would have inundated the channel.

  • It is the sound of our souls escaping from some fissure of the brain.


    James Huneker

  • He walked and walked, and came to a hill: in that hill was a fissure, and in the fissure stood a hut.

    Russian Fairy Tales

    W. R. S. Ralston

  • She peered into the shadowy gulf, but could not see the bottom of the fissure.

    Oh, You Tex!

    William Macleod Raine

  • It did not require long to find a spot where the fissure was easily leaped.

    Two Boys in Wyoming

    Edward S. Ellis

British Dictionary definitions for fissure



any long narrow cleft or crack, esp in a rock
a weakness or flaw indicating impending disruption or discordfissures in a decaying empire
anatomy a narrow split or groove that divides an organ such as the brain, lung, or liver into lobesSee also sulcus
a small unnatural crack in the skin or mucous membrane, as between the toes or at the anus
a minute crack in the surface of a tooth, caused by imperfect joining of enamel during development


to crack or split apart

Word Origin for fissure

C14: from medical Latin fissūra, from Latin fissus split
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fissure

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").

Online Etymology Dictionary, © 2010 Douglas Harper

fissure in Medicine




A deep furrow, cleft, or slit.
A developmental break or fault in the enamel of a tooth.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

fissure in Science



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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.