'Columbium' definitions:
Definition of 'columbium'
From: WordNet
noun
A former name for niobium
Definition of 'Columbium'
From: GCIDE
- Columbium \Co*lum"bi*um\, n. [NL., fr. Columbia America.] (Chem.) A rare element of the vanadium group, first found in a variety of the mineral columbite occurring in Connecticut, probably at Haddam. Atomic weight 94.2. Symbol Cb or Nb. Now more commonly called niobium. [1913 Webster]