[ rey-dee-uhns ]
/ ˈreɪ di əns /


radiant brightness or light: the radiance of the tropical sun.
warm, cheerful brightness: the radiance of her expression.
Rare. radiation.

Nearby words

  1. radial vein,
  2. radial velocity,
  3. radial-ply,
  4. radially,
  5. radian,
  6. radiancy,
  7. radiant,
  8. radiant ,
  9. radiant efficiency,
  10. radiant emittance

Also radiancy.

Origin of radiance

First recorded in 1595–1605; radi(ant) + -ance

Related formsnon·ra·di·ance, nounsub·ra·di·ance, nounsu·per·ra·di·ance, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for radiance

British Dictionary definitions for radiance



/ (ˈreɪdɪəns) /

noun plural -ances or -ancies

the quality or state of being radiant
a measure of the amount of electromagnetic radiation leaving or arriving at a point on a surface. It is the radiant intensity in a given direction of a small element of surface area divided by the orthogonal projection of this area onto a plane at right angles to the directionSymbol: L e
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for radiance



c.1600, "brilliant light," from radiant or else from Medieval Latin radiantia "brightness," from radiare "to beam, shine" (see radiation). Figurative use from 1761. Related: Radiancy.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for radiance


[ rādē-əns ]


The quality or state of being radiant.
The radiant energy emitted per unit time in a specified direction by a unit area of an emitting surface.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.