-(ˌ)ärˌtirēˈōsə̇s noun
also bulbus aor·tae -āˈȯrˌtē
Etymology: New Latin bulbus arteriosus, literally, arterial bulb & bulbus aortae, literally, bulb of the aorta
: the dilated part of the aorta just in front of the heart from which the aortic arches arise in vertebrate embryos and in the adult of many lower vertebrates