I. ˈpinə noun
( plural pin·nae -ˌnē, -ˌnī ; or pinnas )
Etymology: New Latin, from Latin, feather, wing, alteration of penna
1. : a leaflet or primary division of a pinnate leaf or frond
2.
a. : a feather, wing, or fin or some similar part
b. : the largely cartilaginous projecting portion of the external ear — called also auricle ; see ear illustration
II. noun
Etymology: New Latin, from Latin pinna, pina pen shell, from Greek pinē
1. capitalized : the type genus of Pinnidae comprising large wedge-shaped bivalves that have thin shells with a toothless hinge and linear ligament and are attached to the substrate by a long silky byssus
2. plural pinnas or pinnae : pen shell