radiant

What it means

1. Radiating light and/or heat.

   the radiant sun

   2 more examples

   They in ranks / Sat all, where ſtood the fiery ſteeds of each, / And where his radiant arms lay on the field.

   1791, Homer, “[The Iliad.] Book III.”, in W[illiam] Cowper, transl., The Iliad and Odyssey of Homer, Translated into Blank Verse, […], volume I, London: […] J[oseph] Johnson, […], →OCLC, page 79

   The couple's sustainability efforts also included installing radiant heat under the concrete-slab floor.

   2026 May 28, Julie Belcove, “Farm Fresh”, in Architectural Digest, volume 83, number 4, page 93

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

   a radiant face

   2 more examples

   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.

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

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

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

In a sentence

the radiant sun

Where it comes from

1. Latinradiāns
2. Middle Englishradyant
3. Englishradiant

From Middle English radyant, from Latin radiāns, radiantis, present participle of radiāre (“to emit rays or beams”).