Source : Webster's Revised Unabridged Dictionary (1913)

Ovipositor \O`vi*pos"i*tor\, n. [L. ovum an egg + positor a
   placer, fr. ponere to place.] (Zo["o]l.)
   The organ with which many insects and some other animals
   deposit their eggs. Some ichneumon files have a long
   ovipositor fitted to pierce the eggs or larv[ae] of other
   insects, in order to lay their own eggs within the same.

Source : WordNet®

ovipositor
     n : egg-laying tubular structure at the end of the abdomen in
         many female insects and some fishes