The Collaborative International Dictionary of English v.0.48:

Tungstic \Tung"stic\ (t[u^]ng"st[i^]k), a. (Chem.)
   Of or pertaining to tungsten; derived from, or resembling,
   tungsten; wolframic; as, tungstic oxide.
   [1913 Webster]

   Tungstic acid, an acid of tungsten, H2WO4, analogous to
      sulphuric and chromic acids.
      [1913 Webster]

WordNet (r) 3.0 (2006):

tungstic acid
    n 1: an oxyacid of tungsten (often polymeric in nature) formed
         by neutralizing alkaline tungstate solutions