choroid vein vs vena

choroid vein and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
choroid vein	Yes	No	No	No
vena	Yes	No	No	No

As nouns, vena is a hypernym of choroid vein; that is, vena is a word with a broader meaning than choroid vein:

choroid vein: either of two veins serving the choroid coat of the eye
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of choroid vein include vein, venous blood vessel.

choroid vein (noun)	vena (noun)
either of two veins serving the choroid coat of the eye	a blood vessel that carries blood from the capillaries toward the heart