iliac vein vs vena iliaca

iliac vein and vena iliaca both are nouns.

Word	Noun	Adjective	Verb	Adverb
iliac vein	Yes	No	No	No
vena iliaca	Yes	No	No	No

As nouns, iliac vein and vena iliaca are synonyms defined as:

iliac vein (noun)	vena iliaca (noun)
one of three veins draining the pelvic area	one of three veins draining the pelvic area