the quality of being bright.
Optics. the luminance of a body, apart from its hue or saturation, that an observer uses to determine the comparative luminance of another body. Pure white has the maximum brightness, and pure black the minimum brightness.

Origin of brightness

before 950; Middle English brihtnes, Old English beorhtnes. See bright, -ness Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for brightness

Contemporary Examples of brightness

Historical Examples of brightness

  • Do you observe this red glow,—dusky, too, amid all the brightness?

    Other Tales and Sketches

    Nathaniel Hawthorne

  • This flash of gold is the only brightness in the place, otherwise dull and monotonous.

    The Roof of France

    Matilda Betham-Edwards

  • It seemed to them as if the brightness of the moon had been increased, and was as resplendent as that of the sun.

    The Dream

    Emile Zola

  • But there is a light, above the brightness of the sun, shining round about her.

    Slavery Ordained of God

    Rev. Fred A. Ross, D.D.

  • Somehow the brightness had gone from the day—he knew not why.

    Gloria and Treeless Street

    Annie Hamilton Donnell

British Dictionary definitions for brightness



the condition of being bright
physics a former name for luminosity (def. 4)
psychol the experienced intensity of light
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 brightness

Old English beorhtnes "brightness, clearness, splendor, beauty;" see bright + -ness.

Online Etymology Dictionary, © 2010 Douglas Harper