vena comitans vs vena

vena comitans and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena comitans	Yes	No	No	No
vena	Yes	No	No	No

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

vena comitans: a vein accompanying another structure; a vein may accompany an artery in such a way that the arterial pulses aid venous return
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of vena comitans include vein, venous blood vessel.

vena comitans (noun)	vena (noun)
a vein accompanying another structure; a vein may accompany an artery in such a way that the arterial pulses aid venous return	a blood vessel that carries blood from the capillaries toward the heart