Source : Webster's Revised Unabridged Dictionary (1913)

Navicular \Na*vic"u*lar\, a. [L. navicularius, fr. navicula,
   dim. of navis ship: cf. F. naviculaire.]
   1. Of, pertaining to, or resembling, a boat or ship.

   2. Shaped like a boat; cymbiform; scaphoid; as, the navicular
      glumes of most grasses; the navicular bone.

   {Navicular bone}. (Anat.)
      (a) One of the middle bones of the tarsus, corresponding
          to the centrale; -- called also {scaphoid}.
      (b) A proximal bone on the radial side of the carpus; the
          scaphoid.

   {Navicular disease} (Far.), a disease affecting the navicular
      bone, or the adjacent parts, in a horse's foot.

Navicular \Na*vic"u*lar\, n. (Anat.)
   The navicular bone.

Source : WordNet®

navicular
     adj : shaped like a boat [syn: {scaphoid}]
     n : the largest wrist bone on the thumb side [syn: {scaphoid
         bone}, {os scaphoideum}]