n.
Pronunciation: ' ā -tr ē - ə m
Function: noun
Inflected Form: plural atria \ -tr ē - ə \ also atri · ums
Etymology: L
Date: 1577
1 : the central room of a Roman house
2 plural usually atriums a : a rectangular open patio around which a house is built b : a many-storied court in a building (as a hotel) usually with a skylight
3 [ New Latin, from L] : an anatomical cavity or passage especially : the chamber or either of the chambers of the heart that receives blood from the veins and forces it into the ventricle or ventricles ― see HEART illustration
– atri · al \ -tr ē - ə l \ adjective