1) Chamber 2) Concerning a heart chamber 3) Having a courtyard 4) Having an open courtyard 5) Kind of fibrillation 6) Like a courtyard 7) Like part of the heart 8) Like some fibrillation 9) Of a heart chamber 10) Of a heart part 11) Of a patio 12) Of an upper heart chamber 13) Of part of the heart 14) Of Roman rooms 
• (a.) Of or pertaining to an atrium.
pertaining to an atrium.
<anatomy> Pertaining to an atrium. ... (16 Dec 1997) ... 
(a´tre-әl) pertaining to an atrium.
Relating to the atrium or atria of the heart
A'tri·al adjective Of or pertaining to an atrium. 
Relating to an atrium.
Type: Term Pronunciation: ā′trē-ăl Definitions: 1. Relating to an atrium.
Atrial: Pertaining to the atria, the upper chambers of the heart, as in atrial fibrillation and atrial septal defect.
[adj] - (anatomy) of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart)
atrial Relating to or belonging to an atrium.
adjective of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart)