Architecture .

Also called cavaedium. the main or central room of an ancient Roman house, open to the sky at the center and usually having a pool for the collection of rain water.

a courtyard, flanked or surrounded by porticoes, in front of an early or medieval Christian church.

a skylit central court in a contemporary building or house.

Anatomy . either of the two upper chambers on each side of the heart that receive blood from the veins and in turn force it into the ventricles.

noun

close , courtyard , enclosure , quad , quadrangle , yard , cavity , chamber , court , entrance , passage , room