cephalic vein vs vena

cephalic vein and vena both are nouns.

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

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

cephalic vein: a large vein of the arm that empties into the axillary vein
vena: a blood vessel that carries blood from the capillaries toward the heart

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

cephalic vein (noun)	vena (noun)
a large vein of the arm that empties into the axillary vein	a blood vessel that carries blood from the capillaries toward the heart