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

Both cameras capture good detail and color (for a tablet) without overdoing the brightness. —PC Magazine, 21 May 2025

Other steps to help reduce damage include face masks or glasses made to shield blue light, or just simply lowering the brightness of your phone. —Joshua Rapp Learn, Discover Magazine, 21 May 2025

The screen itself is a 3.3K dual-layer OLED affair rated for peak brightness of 1,600 nits. —Abhimanyu Ghoshal, New Atlas, 20 May 2025

Adjust your screen brightness: Use your device's settings to match the screen brightness to the room's lighting. —Sarah Bence, Health, 19 May 2025

Word History

First Known Use

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

Rhymes for brightness

• lightness
• rightness
• tightness
• whiteness
• politeness
• uprightness

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