n.
The first chamber in the heart of fish, amphibians, and reptiles, which receives blood from the veins and contracts to force the blood into the atrium.
[New Latin sinus vēnōsus : Medieval Latin sinus, sinus + Latin vēnōsus, venous.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
