manganic acid

from WordNet (r) 3.0 (2006)

manganic acid
    n 1: a dibasic acid (H2MnO4) found only in solution and in
         manganate salts

from The Collaborative International Dictionary of English v.0.48

manganic acid \manganic acid\ n.
   A dibasic acid {H2MnO4}, formed from manganese, analogous to
   sulphuric acid; it is found only in solution and in manganate
   salts.
   [1913 Webster + WordNet 1.5]