NIOBOUS Meaning of NIOBOUS in English /nuy oh"beuhs/ , adj.1. Chem. containing trivalent niobium, as niobous chloride, NbCl 3 . 2. of or pertaining to niobium. [ 1860-65; NIOB(IUM) + -OUS ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012