The Collaborative International Dictionary of English v.0.48:

Columbic \Co*lum"bic\, a. [From Columbium.] (Chem.)
   Pertaining to, or containing, columbium or niobium; niobic.
   [1913 Webster]

   Columbic acid (Chem.), a weak acid derived from columbic or
      niobic oxide, Nb2O5; -- called also niobic acid.
      [1913 Webster]