柯林斯詞典semilunar valve 1. N either of two crescent-shaped valves, one in the aorta and one in the pulmonary artery, that prevent regurgitation of blood into the heart 半月瓣[anatomy] 返回 semilunar valve劍橋詞典one of the valves (= structures that open and close ) that stop blood from returning into the ventricles (= lower spaces ) of the heart 半月瓣 返回 semilunar valve