What is a blood clotting disorder called?

Depends: Disorders causing defective/inadequate clotting may be referred to as bleeding diathesis and each disorder has its own name, e.g., hemophilia, von willebrand disease, itp etc. Excessive clotting disorders may be called thrombophilia but each type of disorder has its own name, e.g. Leiden factor v mutation, prothrombin mutation, ttp etc.