Pinna

n.	1.	(Bot.) A leaflet of a pinnate leaf. See Illust. of Bipinnate leaf, under Bipinnate.
	2.	(Zool.) One of the divisions of a pinnate part or organ.
	3.	(Zool.) Any species of Pinna, a genus of large bivalve mollusks found in all warm seas. The byssus consists of a large number of long, silky fibers, which have been used in manufacturing woven fabrics, as a curiosity.
	4.	(Anat.) The auricle of the ear. See Ear.

Noun	1.	pinna - division of a usually pinnately divided leaf Synonyms: pinnule
	2.	pinna - the externally visible cartilaginous structure of the external ear Synonyms: auricle, ear

leaflet, pinnule