bril·liant 
(brĭlyənt)
(brĭlyənt)adj.
1. Full of light; shining. See Synonyms at bright.
2. Relating to or being a hue that has a combination of high lightness and strong saturation.
3. Sharp and clear in tone: a recording with brilliant sound.
4. Glorious; magnificent: the brilliant court life at Versailles.
5. Superb; wonderful: The soloist gave a brilliant performance.
6. Having or showing unusual and impressive intelligence: a brilliant mind; a brilliant solution to the problem. See Synonyms at intelligent.
n.
A precious gem, especially a diamond, finely cut in any of various forms with numerous facets.
[French brillant, present participle of briller, to shine, from Italian brillare, perhaps from brillo, beryl, from Latin bēryllus; see BERYL.]
brilliant·ly adv.
brilliant·ness n.