Crevasse

·noun A breach in the levee or embankment of a river, caused by the pressure of the water, as on the lower Mississippi.

II. Crevasse ·noun A deep crevice or fissure, as in embankment; one of the clefts or fissure by which the mass of a glacier is divided.

crevasse
(French, a disruption.) The breaking away of the embankments or levees on the lower Mississippi, by ...

Dictionary of American Words And Phrases by John Russell Bartlett.