Crevasse /(kr?`v?s")/

Cre·vasse

Crevasse

n.
  1. A deep crevice or fissure, as in embankment; one of the clefts or fissure by which the mass of a glacier is divided.
  2. A breach in the levee or embankment of a river, caused by the pressure of the water, as on the lower Mississippi. [U.S.]