niobium

noun2

1. •
   A chemical element (symbol Nb) with an atomic number of 41: a light grey, crystalline, ductile transition metal used in superconducting materials.

   • One should use hypoallergenic jewelry made of surgical grade stainless steel, titanium, 14- or 18-karat gold, or niobium, especially for initial piercings. — 2024
2. •
   A single atom of this element.