What does X, factor mean in medical term?

X, factor means: Factor X: This is a coagulation factor. It’s a blood substance that aids in normal clotting. Factor X can be produced in the liver using vitamin K. It is found in band 13q34 on chromosome 13.
(in Medical Dictionary)

What else does X, factor mean?

Roman numeral 10 is represented by the “X” in factor “X”. Roman numerals are used for all numbered coagulation factor numbers. Factor X was created because of a genetic condition that the factor does not exist.
(in Medical Dictionary)

A factor X defect is an autosomal recessive trait that causes prolonged nose bleeds and gastrointestinal bleeding. It can also cause menorrhagia, hematuria blood, hemarthrosis, abnormally heavy periods, and a severe case of perinatal hemorhage. Factor X deficiency can lead to adverse outcomes for fetuses, such as premature birth, spontaneous abortion and placental abruption.
(in Medical Dictionary)

Stuart-Prower Factor is sometimes called factor X because Miss Prower and Mr. Stuart were first to be diagnosed with a deficiency in this factor.
(in Medical Dictionary)