Source : Webster's Revised Unabridged Dictionary (1913)

Vermicide \Ver"mi*cide\, n. [L. vermis a worm + caedere to
   kill.]
   A medicine which destroys intestinal worms; a worm killer.
   --Pereira.

Source : WordNet®

vermicide
     n : an agent that kills worms (especially those in the
         intestines)