fissure

Etymology

From Middle English fissure, from Old French fissure, from Latin fissūra (“a cleft, chink”), from findō (“to cleave, split, divide”) + -tūra (nominal suffix).

noun

1. A long, narrow crack or opening made by breaking or splitting, especially in rock or earth.
   After Miller's Dale Junction, the main Derby-Manchester line crosses the Wye for the last time and turns north-west up Great Rocks Dale, a natural fissure several miles long. 1960 April, J. P. Wilson, E. N. C. Haywood, “The route through the Peak—Derby to Manchester: Part Two”, in Trains Illustrated, page 224
2. (anatomy) A groove, deep furrow, elongated cleft or tear between body parts or in the substance of an organ; a sulcus.
3. (anatomy) A break or slit in tissue usually at the junction of skin and mucous membrane.
4. A state of incompatibility or disagreement.

verb

1. To split, forming fissures.