1. (n.) A leaflet of a pinnate leaf. See 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.

Eustachian tube alembic auditory apparatus auditory canal auditory meatus auditory nerve auditory ossicles auditory tube auricle basilar membrane bony labyrinth caldron cauliflower ear cochlea conch concha crucible drumhead ear ear lobe eardrum endolymph engine external ear hammer incus inner ear lathe lobe lobule lug machine malleus mastoid process melting pot middle ear mortar motor organ of Corti outer ear oval window perilymph pinna retort round window secondary eardrum semicircular canals shell stapes stirrup test tube transducer transformer tympanic cavity tympanic membrane tympanum vestibule