Source : Webster's Revised Unabridged Dictionary (1913)

Throw \Throw\, v. i.

   {To throw back}, to revert to an ancestral type or character.
      ``A large proportion of the steerage passengers throw back
      to their Darwinian ancestry.'' --The Century. Throwing
stick \Throw"ing stick`\ (Anthropol.)
   An instrument used by various savage races for throwing a
   spear; -- called also {throw stick} and {spear thrower}. One
   end of the stick receives the butt of the spear, as upon a
   hook or thong, and the other end is grasped with the hand,
   which also holds the spear, toward the middle, above it with
   the finger and thumb, the effect being to bring the place of
   support nearer the center of the spear, and practically
   lengthen the arm in the act of throwing.

Source : WordNet®

spear thrower
     n : a sling-like device used in various primitive societies to
         propel a dart or spear [syn: {throwing stick}, {throwing
         board}, {dart thrower}]