The Collaborative International Dictionary of English v.0.48:

Unguis \Un"guis\, n.; pl. Ungues. [L., nail, claw, or hoof.]
   1. The nail, claw, talon, or hoof of a finger, toe, or other
      appendage.
      [1913 Webster]

   2. (Zool.) One of the terminal hooks on the foot of an
      insect.
      [1913 Webster]

   3. (Bot.) The slender base of a petal in some flowers; a
      claw; called also ungula.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unguis
    n 1: any rigid body structure composed primarily of keratin
         [syn: horny structure, unguis]