clotting time [AS, clott] , (Obsolete) the time required for blood to form a clot, tested by collecting a small sample of blood in a glass tube and examining it for clot formation. The first appearance of a clot is noted and timed. The normal coagulation time in glass tubes is 5 to 15 minutes. This simple test has been used to diagnose hemophilia, but it does not detect mild coagulation disorders. It is rarely used in clinical practice. Also called prothrombin time. Compare bleeding time.
