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

• 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

This means that the light source features red, green and blue lasers that merge for 5,000 ANSI lumens brightness and 110% coverage of the BT.2020 color space. —New Atlas, 15 Aug. 2025

For brightness and crunch, the salad is tossed with a citrus vinaigrette and, just before serving, garnished with cilantro and smoked almonds. —Cameron Beall, Southern Living, 14 Aug. 2025

The original ordinance restricted the use of searchlights, while newer ones cover everything from outdoor lighting brightness to directing light downward, keeping light pollution minimal. —Stefanie Waldek, AFAR Media, 12 Aug. 2025

The most valuable utility players in smaller roles include Ben Race, Samantha Coty and Kwabena Addai-Boateng, all of whom bring brightness and enthusiasm without making the smiles seem forced or phony. —Christopher Arnott, Hartford Courant, 12 Aug. 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