atrium

noun

atri·​um ˈā-trē-əm 

plural atria ˈā-trē-ə  also atriums

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 (such as a hotel) usually with a skylight

3

[New Latin, from Latin] : 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

atrial

ˈā-trē-əl 

adjective

Did you know?

In an ancient Roman house, an atrium was an open central court that contained the impluvium, a basin where rainwater collected. It originally contained the hearth and functioned as the center of family life. The term later came to be used for the open front courtyard of a Christian basilica, where congregants collected before services. The atrium was revived in the 20th century in the form of glass-covered, greenery-filled multistory spaces sometimes found in shopping centers, office buildings, and large hotels.

Examples of atrium in a Sentence

Recent Examples on the Web

The ship’s three-story atrium showcases the sea through a massive wall of glass, offering views from various levels, including from the champagne bar, the coffee shop, or a classy club chair in the Dolce Vita bar. —AFAR Media, 3 July 2025

Last December, Pinky’s by Vanderpump opened with its green and glassy atrium right on Las Vegas Boulevard. —Andy Wang, Forbes.com, 2 July 2025

The atrium within the college’s main entrance is undergoing improvements funded through a $500,000 grant from the Illinois Department of Commerce and Economic Opportunity, college spokesperson Kellie Martin confirmed Tuesday. —Olivia Stevens, Chicago Tribune, 1 July 2025

Photo : Nils Timm The formal dining room is flanked by a central glass atrium. —Wendy Bowman, Robb Report, 12 June 2025

Word History

Etymology

Latin

First Known Use

1577, in the meaning defined at sense 1

Kids Definition

atrium

noun

atri·​um ˈā-trē-əm 

plural atria -trē-ə  also atriums

: a chamber of the heart receiving blood from the veins and forcing it into a ventricle that in lung-breathing vertebrates (as frogs and human beings) is one of two chambers of which the right receives blood full of carbon dioxide from the body and the left receives oxygen-rich blood from the lungs but in gill-breathing vertebrates (as fishes) is only a single chamber

Medical Definition

atrium

noun

atri·​um ˈā-trē-əm 

plural atria -trē-ə  also atriums

: an anatomical cavity or passage

especially : a chamber of the heart that receives blood from the veins and forces it into a ventricle or ventricles