Cirque (noun)

1. A circular or semicircular basin, typically with steep walls, formed by glacial erosion.
2. An amphitheater-like valley, typically formed by glacial erosion.

Origin:

From french cirque, from latin circus. the term cirque was first used in the 18th century to refer to an amphitheater-like valley.

Examples:

1. The hikers were in awe of the cirque they had reached.
2. The mountain had a cirque at its summit.
3. The cirque was formed by glacial erosion.
4. The cirque was a popular spot for rock climbing.
5. The cirque was surrounded by steep walls and had a small lake at its bottom.