Latin. n. Feather, wing, fin, battlement parapet, spire steeple, flap, water wheel paddle. - n. Lobe (of the liver). - (Bot.) (a) A leaflet of a pinnate leaf. (b) One of the primary divisions of a decompound leaf. (Zool.) One of the divisions of a pinnate part or organ. (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. (Anat.) The auricle of the ear. See Ear.