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 restaurant takes its name from the Greek goddess of the moon and features a retractable-roof atrium that opens to the sky. —Shivani Vora, Forbes.com, 19 June 2026

The villa is still being excavated and studied, but archaeologists have so far uncovered a grand entrance hall with an atrium and sunken basin, known as an impluvium, surrounded by a mosaic floor with black and white botanical and geometric designs. —Barbie Latza Nadeau, CNN Money, 19 June 2026

Designed to blur the line between indoors and outdoors, the home is organized as a series of pavilions surrounding a massive central atrium with a reflecting pool, sculptural curves, and a distinctive grid-like roof supported by colossal columns. —Mark David, Robb Report, 18 June 2026

Back in town, quench your thirst at the upstairs atrium of Three Bears Brewery & Restaurant, then take the Banff Gondola 7,000 feet up Sulphur Mountain, with views of six mountain ranges and the Bow Valley far below. —Rebecca Deurlein, Travel + Leisure, 17 June 2026

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