auricle vs auricula atrii

auricle and auricula atrii both are nouns.

Word	Noun	Adjective	Verb	Adverb
auricle	Yes	No	No	No
auricula atrii	Yes	No	No	No

As nouns, auricle and auricula atrii are synonyms defined as:

auricle and auricula atrii: a small conical pouch projecting from the upper anterior part of each atrium of the heart

Other synonyms of auricle include atrial auricle.

auricle (noun)	auricula atrii (noun)
a small conical pouch projecting from the upper anterior part of each atrium of the heart	a small conical pouch projecting from the upper anterior part of each atrium of the heart
the externally visible cartilaginous structure of the external ear