1. A four-cornered, four-sided courtyard, usually surrounded by buildings.

2. The buildings surrounding such a courtyard.

3. A four-cornered, four-sided building.

A four- sided tract of land, defined by parallels of latitude and meridians of longitude, used as an area unit in systematic mapping.

A geometric figure bounded by four straight-line segments called sides, each of which intersects each of two adjacent sides in points called vertices, but fails to intersect the opposite sides. Also known as quadrilateral.