The Collaborative International Dictionary of English v.0.48:

Vomitive \Vom"i*tive\, a. [Cf. F. vomitif.]
   Causing the ejection of matter from the stomach; emetic.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vomitive
    n 1: a medicine that induces nausea and vomiting [syn: emetic,
         vomit, vomitive, nauseant]