1823, of glaciers; 1814, of riverbanks (from Louisiana Fr.), from Fr. crevasse, from O.Fr. crevace "crevice" (see crevice). Essentially the same word as crevice, but re-adopted in senses for which the sense that had taken hold in crevice was felt to be too small.
A deep fissure in a glacier or other body of ice. Crevasses are usually caused by differential movement of parts of the ice over an uneven topography.
A large, deep fissure in the Earth caused by an earthquake.
A wide crack or breach in the bank of a river. Crevasses usually form during floods. ◇ The sediments that spill out through the crevasse and fan out along the external margin of the river's bank form a crevasse splay deposit.