n. pl. a·tri·a (ātrē-ə) or a·tri·ums
1. Architecture A rectangular court, as:
a. A usually skylit central area, often containing plants, in some modern buildings, especially of a public or commercial nature.
b. The open area in the center of an ancient Roman house.
c. The forecourt of a building, such as an early Christian church, enclosed on three or four sides with porticoes.
2. Anatomy A body cavity or chamber, especially either of the upper chambers of the heart that receives blood from the veins and forces it into a ventricle. Also called auricle.
[Latin ātrium; see āter- in the Appendix of Indo-European roots.]
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