prothrombin accelerator vs accelerator factor

prothrombin accelerator and accelerator factor both are nouns.

Word	Noun	Adjective	Verb	Adverb
prothrombin accelerator	Yes	No	No	No
accelerator factor	Yes	No	No	No

As nouns, prothrombin accelerator and accelerator factor are synonyms defined as:

Other synonyms of prothrombin accelerator include factor V, proaccelerin.

prothrombin accelerator (noun)	accelerator factor (noun)
a coagulation factor	a coagulation factor