The Collaborative International Dictionary of English v.0.48:

Ferric \Fer"ric\, a. [L. ferrum iron: cf. F. ferrique. See
   Ferrous.]
   Pertaining to, derived from, or containing iron. Specifically
   (Chem.), denoting those compounds in which iron has a higher
   valence than in the ferrous compounds; as, ferric oxide;
   ferric acid.
   [1913 Webster]

   Ferric acid (Chem.), an acid, H2FeO4, which is not known
      in the free state, but forms definite salts, analogous to
      the chromates and sulphates.

   Ferric oxide (Chem.), sesquioxide of iron, Fe2O3;
      hematite. See Hematite.
      [1913 Webster]