an·ti·he·mo·phil·ic factor (ān'tē-hē'mə-fĭl'ĭk, ān'tī-) n.
Abbr. AHF A protein substance in blood plasma that participates in and is essential for the blood-clotting process. Most cases of hemophilia are caused by a deficiency of this factor. Also called antihemophilic globulin, factor VIII.