From Middle English radyant, from Latin radiāns, radiantis, present participle of radiāre.

• IPA: /ˈɹeɪ.di.ənt/

radiant

1. Radiating light and/or heat.

   the radiant sun

2. Emitted as radiation.
3. Beaming with vivacity and happiness.

   a radiant face

   • 1907 August, Robert W[illiam] Chambers, chapter I, in The Younger Set, New York, N.Y.: D. Appleton & Company, →OCLC ↗:

     His sister, Mrs. Gerard, stood there in carriage gown and sables, radiant with surprise. ¶ “Phil !  You !  Exactly like you, Philip, to come strolling in from the antipodes—dear fellow !” recovering from the fraternal embrace and holding both lapels of his coat in her gloved hands.

   • 1961 November 10, Joseph Heller, “The Soldier in White”, in Catch-22 […], New York, N.Y.: Simon and Schuster, →OCLC ↗, page 171 ↗:

     Nurse Cramer had a cute nose and a radiant, blooming complexion dotted with fetching sprays of adorable freckles that Yossarian detested.

4. Strikingly beautiful.
   • 1893, E. Werner, Clear the Track!, page 94:

     And yet she was ensnaringly beautiful, despite her pride and self-consciousness; radiant and certain of conquest she stood before the man who alone seemed to have neither eye nor ear for charms that had never elsewhere played her false.

5. Emitting or proceeding as if from a center.
6. (heraldry) Giving off rays; said of a bearing.

   the sun radiant;  a crown radiant

7. (botany) Having a ray-like appearance, like the large marginal flowers of certain umbelliferous plants; said also of the cluster which has such marginal flowers.

• Italian: radiante
• Russian: светиться
• Spanish: radiante

• Russian: лучи́стый

• Portuguese: radiante
• Russian: лучеза́рный
• Spanish: radiante

radiant (plural radiants)

1. A point source from which radiation is emitted.
2. (astronomy) The apparent origin, in the night sky, of a meteor shower.
3. (geometry) A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve.

• Russian: излуча́тель

• German: Radiant
• Russian: радиа́нт
• Spanish: punto radiante