auricular appendage vs auricular appendix

auricular appendage and auricular appendix both are nouns.

Word	Noun	Adjective	Verb	Adverb
auricular appendage	Yes	No	No	No
auricular appendix	Yes	No	No	No

As nouns, auricular appendage and auricular appendix are synonyms defined as:

auricular appendage and auricular appendix: a pouch projecting from the top front of each atrium of the heart

Other synonyms of auricular appendage include auricula.

auricular appendage (noun)	auricular appendix (noun)
a pouch projecting from the top front of each atrium of the heart	a pouch projecting from the top front of each atrium of the heart