WordWeb Online

1. So thin as to transmit light
   "vaporous silks";
   - diaphanous, filmy, gauzy, gauze-like, gossamer, see-through, sheer, transparent, vapourous [Brit, non-standard], cobwebby, vapoury [Brit, Cdn], vapory [US]
    
2. Resembling or characteristic of vapour
   "vaporous clouds";
   - vaporific, vapourific [Brit, Cdn], vaporish [US], vapourish [Brit, Cdn], vapourous [Brit, non-standard], vapoury [Brit, Cdn], vapory [US]
    
3. Filled with vapour
   "a vaporous bog";
   - miasmal, miasmic, vapourous [Brit, non-standard], vapoury [Brit, Cdn], vapory [US]

See also: cloudy, gaseous, thin