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 atmosphere in the room is respectful—everyone seems moved to be in her presence—but there is a brightness to Gisèle that none of us quite expects. —Gaby Wood, Vogue, 21 Feb. 2026

Above all, the contrast between the information overload and brightness inside the store and the extreme lack of human heart within it was striking to me. —Blake Simons, Variety, 20 Feb. 2026

The brightness of this cluster allowed researchers to use XRISM data to map the motion of gas both around the center of the cluster and further out from its heart. —Robert Lea, Space.com, 20 Feb. 2026

For photographers, this is a good window to dial in exposure settings while the Moon is still near full brightness. —Ryan Brennan, Kansas City Star, 19 Feb. 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