right atrium righ·tat·rium uncommon noun 1. the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus Synonymsright atriumright atrium of the heartatrium dextrum Related words Word family right atrium of the heart Broader terms atrium cordis WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
