columbium(n = noun.substance) - a former name for niobium;
is a kind of atomic number 41, nb, niobium
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
columbium, n. US Chem. = NIOBIUM.