Pronunciation: ā′trē-ŭm, ā′trē-ă
- A chamber or cavity to which are connected several chambers or passageways.
- That part of the tympanic cavity that lies immediately deep to the tympanic membrane.
- In the lung, a subdivision of the alveolar duct from which alveolar sacs open.
Synonym(s): atrium of heart
[L. entrance hall]