The Collaborative International Dictionary of English v.0.48:

Ungula \Un"gu*la\, n.; pl. Ungulae. [L., a claw, hoof, from
   unguis a nail, claw, hoof.]
   1. A hoof, claw, or talon.
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   2. (Geom.) A section or part of a cylinder, cone, or other
      solid of revolution, cut off by a plane oblique to the
      base; -- so called from its resemblance to the hoof of a
      horse.
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   3. (Bot.) Same as Unguis, 3.
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   Spherical ungula (Geom.), a part of a sphere bounded by two
      planes intersecting in a diameter and by a line of the
      surface of the sphere.
      [1913 Webster]