portal vein vs portal

portal vein and portal both are nouns.

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

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

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

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