atrium
/ˈeɪ.tɹi.əm/ noun
Forms atria atriums
- noun (architecture) A central room or space in ancient Roman homes, open to the sky in the middle; a similar space in other buildings.
- noun (architecture) A square hall lit by daylight from above, into which rooms open at one or more levels.
- noun (anatomy) A cavity, entrance, or passage.
- noun (biology) Any enclosed body cavity or chamber.
- noun (anatomy) An upper chamber of the heart that receives blood from the veins and forces it into a ventricle. In higher vertebrates, the right atrium receives blood from the superior vena cava and inferior vena cava, and the left atrium receives blood from the left and right pulmonary veins.
- noun (anatomy) A microscopic air sac within a pulmonary alveolus.
- noun (palynology) A cavity inside a porate aperture of a pollen grain formed by the separation of the sexine and nexine layers, widening toward the interior of the grain.
Synonyms
Etymology
From Latin ātrium (“entry hall”), from Etruscan.
Webster’s 1913
- noun (a) A square hall lighted from above, into which rooms open at one or more levels.
- noun The main part of either auricle of the heart as distinct from the auricular appendix. Also, the whole articular portion of the heart.
Etymology [L., the fore court of a Roman house.]
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “atrium”, CC BY-SA 4.0. Details