Quadrangle (noun)

1. A figure with four sides and four angles.
2. A four-sided area surrounded by buildings, especially a courtyard.
3. A flat-topped mountain peak with four steep sides.

Origin:

Late middle english: from old french, from quadri- "four" + -angle "angle".

Examples:

1. The quadrangle of the castle was surrounded by battlements and towers.
2. The students used the quadrangle as a place to relax and study.
3. The climbers had to cross a dangerous and exposed quadrangle to reach the summit.
4. The mathematical concept of a quadrangle is used in geometry to describe a shape with four sides.
5. The aerial view of the quadrangle showed its perfect geometric symmetry.