colic vein vs vena

colic vein and vena both are nouns.

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

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

colic vein: vein serving the large intestine
vena: a blood vessel that carries blood from the capillaries toward the heart

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

colic vein (noun)	vena (noun)
vein serving the large intestine	a blood vessel that carries blood from the capillaries toward the heart