fac·tor VIII (also factor 8, factor eight) BrE /ˌfæktər ˈeɪt/ 🔊NAmE /ˌfæktər ˈeɪt/ 🔊 noun [uncountable] (biology 生物) a substance in the blood that helps it to clot (= become thick) 因子 VIII;凝血因子 VIII