The Collaborative International Dictionary of English v.0.48:

Vaporific \Vap`o*rif"ic\, a. [L. vapor vapor + facere to make.]
   (Chem.)
   Producing vapor; tending to pass, or to cause to pass, into
   vapor; thus, volatile fluids are vaporific; heat is a
   vaporific agent.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vaporific
    adj 1: (used of substances) capable of being volatilized [syn:
           evaporable, vaporific, vapourific, vaporizable,
           vapourisable, volatilizable, volatilisable]
    2: resembling or characteristic of vapor; "vaporous clouds"
       [syn: vaporific, vapourific, vaporish, vapourish,
       vaporous, vapourous]