The Collaborative International Dictionary of English v.0.48:

Vermifugal \Ver*mif"u*gal\, a. [L. vermis a worm + fugare to
   drive away, fr. fugere to flee. See Worm, and Fugitive.]
   (Med.)
   Tending to prevent, destroy, or expel, worms or vermin;
   anthelmintic.
   [1913 Webster]