English Reference
adjective · noun

radiant

adj. · n.
US /ˈɹeɪˌdiənt/ UK /ɹˈeɪdiənt/ ra·di·ant UK spelling radiants

  1. 01 B2 Upper Intermediate

    adj.sending out light or heat in a way that is bright and warm.

    adj.emitting light or heat through radiation; shining brightly.

    Simple

    The radiant sun warmed the beach early in the morning.

    In context

    The radiant heat from the fireplace was enough to warm the entire living room despite the freezing temperatures outside.

  2. 02 B2 Upper Intermediate

    adj.looking very happy, healthy, or full of love.

    adj.manifesting great joy, love, or health through one's facial expression or physical appearance.

    Simple

    She looked radiant in her white dress on her wedding day.

    In context

    The winner gave a radiant smile to the cameras, clearly overwhelmed by the unexpected victory.

  3. 03 C1 Advanced Technical Science

    adj.describing energy that travels in waves, like heat from a heater.

    adj.transmitted or emitted by radiation rather than conduction or convection.

    Simple

    The new heating system uses radiant energy to keep the floors warm.

    In context

    Scientists measured the radiant flux of the star to determine its total energy output over the course of a year.

  4. 04 C2 Proficiency Technical Astronomy

    n.the point in the sky where a group of shooting stars seems to start.

    n.the point in the celestial sphere from which the paths of meteors in a shower appear to originate.

    Simple

    To see the meteors, look toward the radiant in the constellation Perseus.

    In context

    Observers noted that the radiant of the meteor shower shifted slightly as the Earth moved through the debris field.

He also said putting an e-vehicle near a radiant heat source can cause an explosion.

Toronto Sun· 21 Aug 2026

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

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin radiāns
Level B2 · Upper Intermediate
Frequency Frequent
Updated