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

In addition to the undertone, brightness also plays a decisive role in figuring out the best color combinations. —Jana Ackermann, Glamour, 28 Mar. 2026

Over time, such disks can build up and then disperse, causing the brightness of the star to fluctuate. —Robert Lea, Space.com, 25 Mar. 2026

While steeped in tradition, her recipes feel modern too, finding brightness through herby, vinegar-laden sauces that top seasonal dishes. —The Bon Appétit, Bon Appetit Magazine, 20 Mar. 2026

Inside is a truly enormous 10-inch Dynamic AMOLED 2X screen with a resolution of 2,160 by 1,583 pixels (269ppi), a 120Hz refresh rate, and a maximum brightness of 1,600 nits. —Iyaz Akhtar, PC Magazine, 20 Mar. 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