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

And for clue 2, take the big staircase inside the center’s atrium to the second floor. —Pam Kragen, San Diego Union-Tribune, 25 Apr. 2026

In practice, that meant no grand entrance, no soaring atrium meant to announce the institution’s importance. —John Wogan, Travel + Leisure, 22 Apr. 2026

The backstory The hotel was originally built in 1985 in the garden atrium typology by acclaimed architect Kenneth Treister. —Condé Nast, Condé Nast Traveler, 21 Apr. 2026

Chefs from Brave New Restaurant, The Faded Rose, The Root Cafe, Trios Restaurant and the museum's Park Grill are expected to take part and supply small bites from their restaurants in the museum atrium after the conversation. —Eric E. Harrison, Arkansas Online, 21 Apr. 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