Christmas disease
noun [ U ] medical specialized uk/ˈkrɪs.məs dɪˌziːz/ us/ˈkrɪs.məs dɪˌziːz/
(also haemophilia B)克里斯马斯病，乙型血友病，血友病B
a genetic disease in which there is not enough of a substance called factor IX in the blood, so that the person cannot stop bleeding after an injury