adj. & n.
--adj.
1. very bright; sparkling.
2 outstandingly talented or intelligent.
3 showy; outwardly impressive.
4 colloq. excellent, superb.
--n. a diamond of the finest cut with many facets.
Derivatives:
brilliantly adv.
Etymology: F brillant part. of briller shine f. It. brillare, of unkn. orig.