vena labialis inferior vs inferior labial vein

vena labialis inferior and inferior labial vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena labialis inferior	Yes	No	No	No
inferior labial vein	Yes	No	No	No

As nouns, vena labialis inferior and inferior labial vein are synonyms defined as:

vena labialis inferior and inferior labial vein: a tributary of the facial vein that drains the lower lip

vena labialis inferior (noun)	inferior labial vein (noun)
a tributary of the facial vein that drains the lower lip	a tributary of the facial vein that drains the lower lip