Columbium

noun

1. Niobium. No longer in scientific use.
2. Same as niobium.
3. In chem., a supposed new element announced in 1879 by J. L. Smith as present in the mineral samarskite: its existence has not been confirmed. Distinct from the previously known element columbium or niobium.
4. 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.
5. A former name of niobium/