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 of brightness

• brilliancy
• brilliance
• lightness
• illumination
• luminosity

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 sizes are available with Apple's M5 Pro or M5 Max chips, along with a new OLED display designed to deliver improved brightness, contrast and color accuracy, according to Apple. — ABC News, 29 Oct. 2026

Early signs indicated that its jet was pointed away from Earth, but while the gamma-ray readings were comparatively basic, both its visible and X-ray measurements ranked among the top one percent in brightness. — Andrew Paul, Popular Science, 29 Oct. 2026

Apple also uses dedicated processing algorithms to regulate individual pixels and maintain consistent brightness. — Aamir Khollam, Interesting Engineering, 28 Oct. 2026

Fortunately, there are several effective methods to maintain their brightness and softness. — Anyssa Roberts, The Spruce, 28 Oct. 2026

Word History

First Known Use

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

Rhymes for brightness

• lightness
• rightness
• tightness
• whiteness
• finiteness
• 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