brilliant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Full of light; shining. synonym: bright.
• adjective Relating to or being a hue that has a combination of high lightness and strong saturation.
• adjective Sharp and clear in tone.
• adjective Glorious; magnificent.
• adjective Superb; wonderful.
• adjective Having or showing unusual and impressive intelligence: synonym: intelligent.
• noun A precious gem, especially a diamond, finely cut in any of various forms with numerous facets.

from The Century Dictionary.

• Sparkling with light or luster; glittering; bright: as, a brilliant gem; a brilliant dress.
• Figuratively, distinguished by admirable qualities; splendid; shining: as, a brilliant wit; a brilliant achievement.
• Synonyms Lustrous, radiant, effulgent, resplendent, showy, conspicuous.
• Illustrious, notable.
• noun [Cf. F. brillant, a diamond.] The form in which the diamond and other precious stones are cut when intended to be used as ornaments, whenever the shape and cleavage of the uncut stone allow this to be done without too much loss of material.
• noun The smallest regular size of printing-type, about 20 lines to the inch, very rarely used.
• noun This line is set in brilliant.
• noun In the manège, a brisk, high-spirited horse, with stately action.
• noun A bright light used in fireworks.
• noun A cotton fabric with a raised pattern figured in the loom, and with or without a design in colors.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Sparkling with luster; glittering; very bright.
• adjective Distinguished by qualities which excite admiration; splendid; shining.
• adjective Exceedingly intelligent, or of distinguished accomplishment in a field; -- .
• noun A diamond or other gem of the finest cut, formed into faces and facets, so as to reflect and refract the light, by which it is rendered more brilliant. It has at the middle, or top, a principal face, called the table, which is surrounded by a number of sloping facets forming a bizet; below, it has a small face or collet, parallel to the table, connected with the girdle by a pavilion of elongated facets. It is thus distinguished from the rose diamond, which is entirely covered with facets on the surface, and is flat below.
• noun (Print.) The smallest size of type used in England printing.
• noun A kind of cotton goods, figured on the weaving.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Shining brightly.
• adjective of a colour Both bright and saturated.
• adjective of a voice or sound having a sharp, clear tone
• adjective Of surpassing excellence.
• adjective Magnificent or wonderful.
• adjective Highly intelligent.
• noun A finely cut gemstone, especially a diamond, having many facets.
• noun printing A small size of type.
• noun A kind of cotton goods, figured on the weaving.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective of surpassing excellence
• adjective characterized by grandeur
• adjective clear and sharp and ringing
• adjective having or marked by unusual and impressive intelligence
• adjective having striking color
• adjective full of light; shining intensely