from
The Collaborative International Dictionary of English v.0.48
Pinna \Pin"na\, n.; pl. {Pinn[ae]}, E. {Pinnas}. [L., a
feather.]
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.
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2. (Zool.) One of the divisions of a pinnate part or organ.
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3. [L. pinna, akin to Gr. ?.] (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.
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4. (Anat.) The auricle of the ear. See {Ear}.
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