brightness

noun

bright·​ness ˈbrīt-nəs 

1

a

: the quality or state of being bright

also : an instance of such a quality or state

b

: luminance

2

: the attribute of light-source colors by which emitted light is ordered continuously from light to dark in correlation with its intensity compare hue sense 2c, lightness entry 1 sense 2a, saturation sense 4

Synonyms

• brilliance
• brilliancy
• candor
• dazzle
• effulgence
• illumination
• lambency
• lightness
• luminance
• luminosity
• luminousness
• luster
• lustre
• lustrousness
• radiance
• refulgence
• splendor

Examples of brightness in a Sentence

the brightness of the sunshine made me squint after an afternoon spent in a darkened movie theater

Recent Examples on the Web

Within the first two months of life, babies begin to recognize faces, see the brightness of color and develop depth perception. —Isabella Balandran, Los Angeles Times, 18 Apr. 2024

What to expect This year’s viewing of the Lyrids faces a significant challenge due to the brightness of the waxing gibbous Moon, which will be 96% full at the peak of the shower. —George Dvorsky / Gizmodo, Quartz, 16 Apr. 2024

Those troublesome modes are why the brightness of conventional semiconductor lasers maxes out around 100 MW/cm2/sr. —Susumu Noda, IEEE Spectrum, 14 Apr. 2024

That, along with the brightness of the daytime sky, makes the moon virtually invisible to the human eye. —Chris Mueller, USA TODAY, 12 Apr. 2024

However, the brightness of the lights may be why these gardens are so successful. —Rachel Ahrnsen, Better Homes & Gardens, 11 Apr. 2024

Lemon juice: Adds brightness to the filling. Vanilla: To elevate all the flavors. —Southern Living Test Kitchen, Southern Living, 8 Apr. 2024

During totality, a thin circle of brightness rings the moon. —Rivka Galchen, The New Yorker, 5 Apr. 2024

The color-changing smart bulbs work with all major smart home platforms and light up homes with 1,100 lumens of brightness. —Sheena Vasani, The Verge, 2 Apr. 2024

Word History

First Known Use

before the 12th century, in the meaning defined at sense 1a

Medical Definition

brightness

noun

bright·​ness ˈbrīt-nəs 

: the one of the three psychological dimensions of color perception by which visual stimuli are ordered continuously from light to dark and which is correlated with light intensity compare hue, saturation sense 4a