pinna vs ear

pinna and ear both are nouns.

Word	Noun	Adjective	Verb	Adverb
pinna	Yes	No	No	No
ear	Yes	No	No	No

As nouns, pinna and ear are synonyms defined as:

pinna and ear: the externally visible cartilaginous structure of the external ear

Other synonyms of pinna include auricle.

pinna (noun)	ear (noun)
the externally visible cartilaginous structure of the external ear	the sense organ for hearing and equilibrium
division of a usually pinnately divided leaf	the externally visible cartilaginous structure of the external ear
	good hearing
	attention to what is said
	fruiting spike of a cereal plant especially corn