Source : Webster's Revised Unabridged Dictionary (1913)

Splint \Splint\, n. [Akin to D. splinter,G. splinter, splitter,
   Dan. splint, Sw. splint a kind of spike, a forelock (in
   nautical use), Sw. splintato splint, splinter, Dan. splinte,
   and E. split. See {Split}, v. t., and cf. {Splent}.]
   1. A piece split off; a splinter.

   2. (Surg.) A thin piece of wood, or other substance, used to
      keep in place, or protect, an injured part, especially a
      broken bone when set.

   3. (Anat.) A splint bone.

   4. (Far.) A disease affecting the splint bones, as a
      callosity or hard excrescence.

   5. (Anc. Armor.) One of the small plates of metal used in
      making splint armor. See {Splint armor}, below.

            The knees and feet were defended by splints, or thin
            plates of steel.                      --Sir. W.
                                                  Scott.

   6. Splint, or splent, coal. See {Splent coal}, under
      {Splent}.

   {Splint armor},a kind of ancient armor formed of thin plates
      of metal, usually overlapping each other and allowing the
      limbs to move freely.

   {Splint bone} (Anat.), one of the rudimentary, splintlike
      metacarpal or metatarsal bones on either side of the
      cannon bone in the limbs of the horse and allied animals.
      

   {Splint coal}. See {Splent coal}, under {Splent}.

Source : WordNet®

splint bone
     n : a rudimentary splint-like metacarpal or metatarsal bone on
         either side of the cannon bone in the leg of a horse or
         related animal