labial vein vs vein

labial vein and vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
labial vein	Yes	No	No	No
vein	Yes	No	Yes	No

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

labial vein: a vein draining the lips of the mouth
vein: a blood vessel that carries blood from the capillaries toward the heart

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

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

labial vein: veins draining the lips of the vulva
vein: a blood vessel that carries blood from the capillaries toward the heart

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

labial vein (noun)	vein (noun)
a vein draining the lips of the mouth	one of the horny ribs that stiffen and support the wing of an insect
veins draining the lips of the vulva	a blood vessel that carries blood from the capillaries toward the heart
	a distinctive style or manner
	a layer of ore between layers of rock
	any of the vascular bundles or ribs that form the branching framework of conducting and supporting tissues in a leaf or other plant organ

labial vein (verb)	vein (verb)
	make a veinlike pattern