(n.) A leaflet of a pinnate leaf. See Illust. of Bipinnate leaf, under Bipinnate.
(n.) One of the primary divisions of a decompound leaf.
(n.) One of the divisions of a pinnate part or organ.
(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.