The Collaborative International Dictionary of English v.0.48:

Vermicide \Ver"mi*cide\, n. [L. vermis a worm + caedere to
   kill.]
   A medicine which destroys intestinal worms; a worm killer.
   --Pereira.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vermicide
    n 1: an agent that kills worms (especially those in the
         intestines)

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "vermicide":
   aborticide, acaricide, anthelmintic, antibiotic, antiseptic,
   bug bomb, carbamate insecticide, chemosterilant,
   chlorinated hydrocarbon insecticide, contact poison, defoliant,
   disinfectant, eradicant, fratricide, fumigant, fungicide, genocide,
   germicide, herbicide, homicide, infanticide, insect powder,
   insecticide, matricide, microbicide, miticide, organic chlorine,
   organic phosphate insecticide, parricide, patricide, pesticide,
   poison, rat poison, regicide, roach paste, roach powder,
   rodenticide, sororicide, stomach poison, suicide, systemic,
   systemic insecticide, toxic, toxicant, toxin, uxoricide, venin,
   venom, vermifuge, virus, weed killer, worm medicine