sinus venosus

noun

si·​nus ve·​no·​sus ˈsī-nəs-vi-ˈnō-səs 

: an enlarged pouch that adjoins the heart, is formed by the union of the large systemic veins, and is the passage through which venous blood enters the heart in lower vertebrates and in embryos of higher forms

Word History

Etymology

New Latin, venous sinus

First Known Use

circa 1839, in the meaning defined above

Medical Definition

sinus venosus

noun

si·​nus ve·​no·​sus ˌsī-nəs-vi-ˈnō-səs 

: an enlarged pouch that adjoins the heart, is formed by the union of the large systemic veins, and is the passage through which venous blood enters the heart in lower vertebrates and in embryos of higher forms