A 'fissure' is a narrow opening produced by cleavage or separation of parts. Generally described as a natural division in an organ, as in the brain. It is used in anatomical terms.
It means a split or a cleavage or a vent. It is also a crack or a cleft or sometimes division or factions and schisms.
In terms of medicines, it is a break in the skin.
1) This study reports the observation of fissures on the Sun.
2) There are many fissures in the valley.
3)"Fissures in your body led to this drastic situation", sighed the doctor.
4)Fissures on the skin will lead to dangerous and incurable diseases.
5)Unity of a community might get disrupted due to fissures in thinking among people.