Source : Webster's Revised Unabridged Dictionary (1913)

Prong \Prong\, n. [Cf. D. prangen to pinch, press, LG. prange a
   stick, or W. procio to thrust, E. prowl, pang.]
   1. A sharp-pointed instrument.

            Prick it on a prong of iron.          --Sandys.

   2. The tine of a fork, or of a similar instrument; as, a fork
      of two or three prongs.

   3. (Zo["o]l.)
      (a) A sharp projection, as of an antler.
      (b) The fang of a tooth.

Source : WordNet®

prong
     n : a pointed projection