Source : Webster's Revised Unabridged Dictionary (1913)

Fluosilicic \Flu`o*si*lic"ic\, a. [Fluo- + silicic: cf. F.
   fluosilicique.] (Chem.)
   Composed of, or derived from, silicon and fluorine.

   {Fluosilicic acid}, a double fluoride of hydrogen and
      silicon, {H2F6Si}, obtained in solution in water as a sour
      fuming liquid, and regarded as the type of the
      fluosilicates; -- called also {silicofluoric acid}, and
      {hydrofluosilicic acid}.

Source : WordNet®

hydrofluosilicic acid
     n : an unstable poisonous corrosive acid know primarily in the
         form of its salts [syn: {fluosilicic acid}]