NIOBIUM
niobium, Nb, atomic number
(noun) a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
Source: WordNet® 3.1
Etymology
Noun
niobium (countable and uncountable, plural niobiums)
A chemical element (symbol Nb) with an atomic number of 41: a light grey, crystalline, ductile transition metal used in superconducting materials.
(countable) A single atom of this element.
Synonyms
• columbium (in metallurgy; not in scientific use)
• dianium (obsolete)
Source: Wiktionary
Ni*o"bi*um, n. Etym: [NL., fr. L. & E. Niobe.] (Chem.)
Definition: A later name of columbium. See Columbium.
Source: Webster’s Unabridged Dictionary 1913 Edition