Source : Webster's Revised Unabridged Dictionary (1913)

Piercer \Pier"cer\, n.
   1. One who, or that which, pierces or perforates;
      specifically:
      (a) An instrument used in forming eyelets; a stiletto.
      (b) A piercel.

   2. (Zo["o]l.)
      (a) The ovipositor, or sting, of an insect.
      (b) An insect provided with an ovipositor.