fissure
noun /ˈfɪʃə(r)/
/ˈfɪʃər/
(specialist)- a long deep opening in something, especially in rock or in the earth
- parched grassland dissected by open dry fissures
- fissures in the ocean floor
Word Originlate Middle English: from Old French, or from Latin fissura, from findere ‘to split’.