hsbo3

from The Collaborative International Dictionary of English v.0.48

Metantimonic \Met`an*ti*mon"ic\, a. [Pref. met- + antimonic.]
   (Chem.)
   (a) Pertaining to, or designating, an acid (formerly called
       {antimonic acid}) analogous to metaphosphoric acid, and
       obtained as a white amorphous insoluble substance,
       ({HSbO3}).
   (b) Formerly, designating an acid, which is now properly
       called {pyroantimonic acid}, and analogous to
       {pyrophosphoric acid}.
       [1913 Webster]