parasiticide

from The Collaborative International Dictionary of English v.0.48

Parasiticide \Par`a*sit"i*cide\
   (p[a^]r`[.a]*s[i^]t"[i^]*s[imac]d), n. [Parasite + L. caedere
   to kill.]
   Anything used to destroy parasites. --Quain.
   [1913 Webster]