sigmoid vein vs vena sigmoideus

sigmoid vein and vena sigmoideus both are nouns.

Word	Noun	Adjective	Verb	Adverb
sigmoid vein	Yes	No	No	No
vena sigmoideus	Yes	No	No	No

As nouns, sigmoid vein and vena sigmoideus are synonyms defined as:

sigmoid vein and vena sigmoideus: tributaries of the inferior mesenteric vein; drains the sigmoid colon

sigmoid vein (noun)	vena sigmoideus (noun)
tributaries of the inferior mesenteric vein; drains the sigmoid colon	tributaries of the inferior mesenteric vein; drains the sigmoid colon