radiant

American  

[rey-dee-uhnt] / ˈreɪ di ənt /

adjective

1. emitting rays of light; shining; bright.

   the radiant sun;

   radiant colors.

   Synonyms:

   resplendent, refulgent, beaming

   Antonyms:

   dim

2. bright with joy, hope, etc..

   radiant smiles;

   a radiant future.

3. Physics. emitted or propagated by radiation.

4. Heraldry.

   1. noting a partition line having a series of flamelike indentations formed by ogees joined in zigzags; rayonny.

   2. (of a charge, as an ordinary) having an edge or edges so formed.

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noun

1. a point or object from which rays proceed.

2. Astronomy. the point in the heavens from which a shower of meteors appears to radiate.

3. a refractory absorbing and radiating heat from the flames of a gas fireplace or the like.

radiant British  

/ ˈreɪdɪənt /

adjective

1. sending out rays of light; bright; shining

2. characterized by health, intense joy, happiness, etc

   a radiant countenance

3. emitted or propagated by or as radiation; radiated

   radiant heat

4. sending out heat by radiation

   a radiant heater

5. physics (of a physical quantity in photometry) evaluated by absolute energy measurements Compare luminous

   radiant flux

   radiant efficiency

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noun

1. a point or object that emits radiation, esp the part of a heater that gives out heat

2. astronomy the point in space from which a meteor shower appears to emanate

radiant Scientific  

/ rā′dē-ənt /

1. Transmitting light, heat, or other radiation. Stars, for example, are radiant bodies.

2. Consisting of or transmitted as radiation.

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1. The apparent celestial origin of a meteor shower. For example, a point in the constellation Gemini is the radiant of the Geminid meteor shower.

Synonym Usage

See bright.

Other Word Forms

Derived Forms

• nonradiantly
  adverb
• antiradiant
  adjective
• superradiant
  adjective
• unradiant
  adjective
• radiantly
  adverb
• nonradiant
  adjective

Etymology

Origin of radiant

First recorded in 1400–50; late Middle English, from Latin radiant-, stem of radiāns “shining,” present participle of radiāre “to radiate light, shine,” verb derivative of radius “beam, ray”; see radius

Explanation

The adjective radiant is useful for describing anything that glows with warmth or light. When you open your eyes on a sunny summer morning and see your curtains glowing with sunlight, you can call them radiant. Something that shines or glows is radiant, and you can also describe anything that's bright as radiant, like a smile or a powerful emotion ("a radiant sense of happiness"). In science, radiant means "transmitted by radiation," and it usually describes heat, like the radiant heat from an oven. The Latin root is radiantem, "shining," and sometime around 1500 it started being used to describe physical beauty, which Shakespeare did in "Twelfth Night": "Most radiant, exquisite, and unmatchable beauty..."

Example Sentences

On Saturday, actor Sarah Jessica Parker will join author Alexandra Oliva at the festival to discuss Oliva’s new novel “The Radiant Dark” from Parker’s SJP Lit, an imprint from the independent publisher Zando.

From Los Angeles Times • Apr. 15, 2026

Cembalest cites research by Radiant Energy Group that the cost of restarting Class 2 reactors could be $1 billion to $ 3 billion each.

From MarketWatch • Mar. 9, 2026

Each amazing creature in “The Radiant Sea” has evolved for its specific niche.

From The Wall Street Journal • Nov. 21, 2025

Brad Gooch, author of recent official Haring biography, Radiant: The Life and Line of Keith Haring, saw Luna Luna being reconstructed, describing the feat as "mind boggling."

From BBC • Dec. 22, 2024

Charlotte read the words: “With New Radiant Action.”

From "Charlotte's Web" by E.B. White

Related Words

• beaming
• brilliant
• gleaming
• glittering
• glowing
• incandescent
• lustrous
• resplendent
• shining
• sunny