1.  pinna(n = noun.plant) pinnule - division of a usually pinnately divided leaf;
is a kind of leaflet

2.  pinna(n = noun.body) auricle, ear - the externally visible cartilaginous structure of the external ear;
is a kind of cartilaginous structure
is a part of external ear, outer ear
has parts: ear lobe, earlobe, tragus
has particulars: cauliflower ear

1.  A leaflet of a pinnate leaf. See Illust. of Bipinnate leaf, under Bipinnate. [1913 Webster]

2.  One of the divisions of a pinnate part or organ. [1913 Webster]

3.  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. [1913 Webster]

4.  The auricle of the ear. See Ear. [1913 Webster]

pinna, n. (pl. pinnae or pinnas)
1 the auricle; the external part of the ear.
2 a primary division of a pinnate leaf.
3 a fin or finlike structure, feather, wing, etc.

Etymology:
L, = penna feather, wing, fin