|a protein that participates in the clotting of blood. It is extracted from donated serum and used in the treatment of the commonest type of haemophilia, in which it is absent|
factor VIII n.
A factor in the clotting of blood, a deficiency of which is associated with hemophilia A. Also called antihemophilic factor, antihemophilic globulin, antihemophilic globulin A, proserum prothrombin conversion accelerator.