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.n. [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.n. The smallest regular size of printing-type, about 20 lines to the inch, very rarely used.n. This line is set in brilliant.n. In the manège, a brisk, high-spirited horse, with stately action.n. A bright light used in fireworks.n. A cotton fabric with a raised pattern figured in the loom, and with or without a design in colors.