1. Plural of columbium; the former name for the chemical element niobium (symbol Nb).
Usage: archaic; The term 'columbium' was used primarily in the 19th and early 20th centuries before 'niobium' became the standard IUPAC name.

Examples

• Early chemists referred to samples of the element as columbiums before the modern nomenclature was standardized.
• Historical chemistry texts occasionally mention columbiums in discussions of rare metallic elements.
• The transition from columbiums to niobium reflects the evolution of chemical naming conventions.