| ̷ ̷ ̷ ̷(ˌ)ärˌtirēˈōsəs noun
Etymology: New Latin, arterial trunk
: the part of the arterial system within the pericardium connecting the ventricle and ventral aorta in anamniotes and early developmental stages of amniotes ; specifically : the part of the truncus arteriosus between the bulbus arteriosus and the ventral aorta