Fissure/ˈfɪʃər/ Definition 1 of 4Pro Tip 1/2Physical rupture Use 'fissure' to describe physical breaks, emphasizing they're narrow and elongated. The vase had a hairline fissure running down its side. Pro Tip 2/2Geographical feature 'Fissure' can describe cracks caused by geological events, like earthquakes. Geologists studied the fissure that formed in the valley.