A geometric shape with four angles and four straight sides; a four-sided polygon.
The buildings forming the border of such a courtyard.
A courtyard which is quadrangular.
A quadrilateral with two sides parallel and two sides non-parallel.
The trapezium bone of the wrist.
A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers.
A quadrilateral with two sides parallel.