Noun. 1. pulmonary artery-one of two arteries (branches of the pulmonary trunk) that carry venous blood from the heart to the lungs. arteria pulmonalis. arteria, arterial blood vessel, artery-a blood vessel that carries blood from the heart to the body. pulmonary trunk, truncus pulmonalis-the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries. Translations.