The Collaborative International Dictionary of English v.0.48:

Evaporable \E*vap"o*ra*ble\, a.
   Capable of being converted into vapor, or dissipated by
   evaporation.
   [1913 Webster]

WordNet (r) 3.0 (2006):

evaporable
    adj 1: (used of substances) capable of being volatilized [syn:
           evaporable, vaporific, vapourific, vaporizable,
           vapourisable, volatilizable, volatilisable]