Pin·na n.; pl. Pinnæ E. Pinnas
1. Bot. (a) A leaflet of a pinnate leaf. See Illust. of Bipinnate leaf, under Bipinnate. (b) One of the primary divisions of a decompound leaf.
2. Zool. One of the divisions of a pinnate part or organ.
3. Zool. 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.
4. Anat. The auricle of the ear. See Ear.
◄ ►
Pin·nule n.
1. Bot. One of the small divisions of a decompound frond or leaf. See Illust. of Bipinnate leaf, under Bipinnate.
2. Zool. Any one of a series of small, slender organs, or parts, when arranged in rows so as to have a plumelike appearance; as, a pinnule of a gorgonia; the pinnules of a crinoid.
◄ ►
bipinnate leaf
n : having pinnate leaflets; as ferns