adj. 1. Emitting heat or light: a radiant star. 2. Consisting of or emitted as radiation: radiant heat. 3. Filled with light shining especially as rays; brightly shining: a radiant morning. See Synonyms at bright. 4. a. Showing or expressing vitality or joy: radiant eyes; a radiant smile. b. Splendid; glorious: radiant beauty; a radiant future. n. 1. An object or point from which light or heat rays are emitted. 2. Astronomy The apparent celestial origin of a meteoric shower. [Middle English, from Latin radiāns, radiant-, present participle of radiāre, to radiate; see RADIATE.] radi·ant·ly adv. |
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