varicose vein vs vena

varicose vein and vena both are nouns.

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

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

varicose vein: a vein that is permanently dilated; most common in the legs
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of varicose vein include vein, venous blood vessel, varicosity.

varicose vein (noun)	vena (noun)
a vein that is permanently dilated; most common in the legs	a blood vessel that carries blood from the capillaries toward the heart