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

While some fans may find the premise redundant, the youthful perspective adds just enough brightness to the show’s austere religious world. —Rebecca Aizin, PEOPLE, 10 Apr. 2026

That means its peak brightness may coincide with its most difficult observing conditions. —Jamie Carter, Space.com, 10 Apr. 2026

Barco notes that Lightsteering redistributes existing light instead of demand- ing more, enhancing contrast and brightness without consuming more energy (and adding to energy bills). —Jazz Tangcay, Variety, 9 Apr. 2026

Human eyes are remarkably good at sensing color gradients and brightness changes. —Stephen Clark, ArsTechnica, 9 Apr. 2026

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