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

• brilliance
• brilliancy
• candor
• dazzle
• effulgence
• illumination
• lambency
• lightness
• luminance
• luminosity
• luminousness
• luster
• lustre
• lustrousness
• radiance
• refulgence
• splendor

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

Penn State professor Joel Leja explains that machine learning is completely changing how astronomers process data, enabling rapid analysis of changes in star brightness and revealing orbiting planets. —Shelli Brunswick, Forbes, 5 Nov. 2024

This waterproof light beams up to 400 lumens of brightness, and changes output power with the tap of a finger (no futzing with gloves). —Lisa Jhung, Outside Online, 2 Nov. 2024

Echoes the orange segments in the salad and lends a brightness to the dressing. —Julia Levy, Southern Living, 2 Nov. 2024

The nova, when a star shows a sudden large increase in brightness, will only be visible to the naked eye for less than a week, according to NASA. —Julia Jacobo, ABC News, 31 Oct. 2024

Word History

First Known Use

before the 12th century, in the meaning defined at sense 1a

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