factor x factor viii • factor xi · · · Info · Definitions · Synonyms · Characters · · factor x · · Text Common · · Latin · · Scripts 8 · · Length 3 · · Syllables Definitions · · · (noun) coagulation factor that is converted to an enzyme that converts prothrombin to thrombin in a reaction that depends on calcium ions and other coagulation factors. Synonyms: prothrombinase, factor X. · · Noun Definition 1 Synonyms · · · prothrombinase · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 f latin small letter f U+0066 o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074 x latin small letter x U+0078