Main Entry:

pin·na

Pronunciation:

\ˈpi-nə\

Function:

noun

Inflected Form(s):

plural pin·nae \ˈpi-ˌnē, -ˌnī\ or pinnas

Etymology:

New Latin, from Latin, feather, wing — more at pen

Date:

1719

1 a: a projecting body part (as a feather, wing, or fin) b: the largely cartilaginous projecting portion of the external ear — see ear illustration2: a leaflet or primary division of a pinnate leaf or frond