portal vs portal vein

portal and portal vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
portal	Yes	No	No	No
portal vein	Yes	No	No	No

As nouns, portal and portal vein are synonyms defined as:

Other synonyms of portal include hepatic portal vein, vena portae.

portal (noun)	portal vein (noun)
a grand and imposing entrance (often extended metaphorically)	a short vein that carries blood into the liver
a short vein that carries blood into the liver
a site that the owner positions as an entrance to other sites on the internet