Dictionary.net

a hard gray lustrous metallic element that is highly corrosion-resistant; occurs in niobite and fergusonite and tantalite

a hard gray lustrous metallic element that is highly corrosion-resistant; occurs in niobite and fergusonite and tantalite

Tantalum. A rare metallic element, atomic number 73, atomic weight 180.948, symbol Ta. It is a noncorrosive and malleable metal that has been used for plates or disks to replace cranial defects, for wire sutures, and for making prosthetic devices. (Dorland, 28th ed)

A rare metal seldom seen except as a compound; symbol Ta, atomic weight 181.

A metal, now called columbium.

The metal extracted from tantalite, of a dark-grey colour, very dense and difficult of fusion-also called columbium.