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

Add a burst of brightness to a quieter color scheme by way of vibrant shoes like the chartreuse wedges above. — Amber Rambharose, InStyle, 6 Aug. 2026

An Intensity Slider – a simple sliding bar adjustment for controlling the depth, vibrancy, brightness and contrast of the TV’s pictures to compensate for viewing angles, onscreen reflections and simply different viewing tastes. — John Archer, Forbes.com, 6 Aug. 2026

The team is now working on a field-deployable product by improving brightness and entanglement quality. — Ameya Paleja, Interesting Engineering, 6 Aug. 2026

Now the team is working to boost the source’s brightness and entanglement quality toward a field-deployable device. — Sanidhya Sharma, Scientific American, 6 Aug. 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