[bril.liant] adj [F brillant, prp. of briller to shine, fr. It brillare] (ca. 1681) 1: very bright: glittering "a ~ light"
2. a: striking, distinctive "a ~ example" b: distinguished by unusual mental keenness or alertness syn see bright -- bril.liant.ly adv
[2]brilliant n (1690): a gem (as a diamond) cut in a particular form with numerous facets so as to have special brilliance