brachial vein vs vena brachialis

brachial vein and vena brachialis both are nouns.

Word	Noun	Adjective	Verb	Adverb
brachial vein	Yes	No	No	No
vena brachialis	Yes	No	No	No

As nouns, brachial vein and vena brachialis are synonyms defined as:

brachial vein and vena brachialis: two veins in either arm that accompany the brachial artery and empty into the axillary vein

brachial vein (noun)	vena brachialis (noun)
two veins in either arm that accompany the brachial artery and empty into the axillary vein	two veins in either arm that accompany the brachial artery and empty into the axillary vein