The Collaborative International Dictionary of English v.0.48:

Nasal \Na"sal\, n.
   1. An elementary sound which is uttered through the nose, or
      through both the nose and the mouth simultaneously.
      [1913 Webster]

   2. (Med.) A medicine that operates through the nose; an
      errhine. [Archaic]
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   3. (Anc. Armor) Part of a helmet projecting to protect the
      nose; a nose guard.
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   4. (Anat.) One of the nasal bones.
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   5. (Zool.) A plate, or scale, on the nose of a fish, etc.
      [1913 Webster]