vena stylomastoidea vs stylomastoid vein

vena stylomastoidea and stylomastoid vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena stylomastoidea	Yes	No	No	No
stylomastoid vein	Yes	No	No	No

As nouns, vena stylomastoidea and stylomastoid vein are synonyms defined as:

vena stylomastoidea and stylomastoid vein: a vein that drains the tympanic cavity and empties into the retromandibular vein

vena stylomastoidea (noun)	stylomastoid vein (noun)
a vein that drains the tympanic cavity and empties into the retromandibular vein	a vein that drains the tympanic cavity and empties into the retromandibular vein