Available Definitions:
1) n. - A leaflet of a pinnate leaf. See Illust . of Bipinnate leaf, under Bipinnate.
2) n. - One of the primary divisions of a decompound leaf.
3) n. - One of the divisions of a pinnate part or organ.
4) n. - 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.
5) n. - The auricle of the ear. See Ear .