(from the French) An armchair-shaped hollow with steep sides and back wall, formed as a result of glacial erosion high on a mountainside, and often containing a rock basin with a tarn (q.v.) (known as corrie or cwm in Britain).

The cirque of Cwm Cau on the peak of Cadair Idris, Snowdonia National Park, Wales. Photo M. J. Hambrey.