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

The white-hot brightness of Diana’s spotlight also ensnared her brother, Charles Spencer. — Elise Taylor, Vanity Fair, 29 Sep. 2026

Razer claims the battery will last up to 200 hours with the RGB lighting off, or up to 50 hours with the lights at half brightness. — Brad Bourque, The Verge, 29 Sep. 2026

The screen has a pretty standard 60Hz refresh rate and 300 nits of brightness, but that’s to be expected from any midrange laptop. — Kelsey Fogarty, PC Magazine, 28 Sep. 2026

In some of the new villas, christened Le Ville della Marchesa, details include headboards upholstered with the famous Missoni zigzag and bathrooms that combine the original gray marble with the brightness of Vietri. — Condé Nast, Condé Nast Traveler, 26 Sep. 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