Definition of brightness 

1a : 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 2, saturation sense 4

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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 2018 Frame has built-in sensors that can adjust the screen’s brightness based on the time of day and amount of light in the room. Sunset, "Your Next TV Could Double As Art," 22 Jan. 2018 The sliced pear adds an unexpected brightness to the sandwich, counterbalancing the heavy notes of the beef and blue cheese. Daniel Neman, sacbee, "Main dishes? Fruit is not forbidden," 26 June 2018 When extended to full size (4.7 inches tall), the waterproof lantern — with hanging handle — provides low or high brightness plus an SOS flashing option. Necee Regis,, "Here, there, and everywhere," 12 June 2018 Over the course of its two-year mission, TESS will stare at around 200,000 of the stars closest to Earth, watching for telltale dips in brightness caused by a planet crossing in front of its star. The Economist, "The search for exoplanets moves to Earth’s back yard," 19 Apr. 2018 The mission is to detect brief decreases in brightness caused by a planet cutting across a star., "NASA Is About to Launch a New Planet-Hunter," 29 Mar. 2018 The feel is muscular, almost martial, while sneaking in a bit of bouncy brightness with the rhythmic triplet that leads the melody’s descending notes. Brian Mccollum, Detroit Free Press, "Detroit's global sports anthem: The White Stripes' 'Seven Nation Army'," 29 June 2018 Dell promises 400 nits of maximum brightness, and our tests found that to be accurate. Samuel Axon, Ars Technica, "Dell XPS 15 2-in-1 review: Meet the child of Intel and AMD’s unholy union," 23 May 2018 Okroshka, a cooler summer soup, is made with the same yogurt as in kurut, although here the salt has subsided; crisp radish and dill lend brightness, and a quail egg, chopped, a hint of cream. Ligaya Mishan, New York Times, "At Cafe Dushanbe, a Chef Stays True to His Tajik Roots," 21 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'brightness.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of brightness

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

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Last Updated

12 Oct 2018

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Time Traveler for brightness

The first known use of brightness was before the 12th century

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More Definitions for brightness


bright·ness | \ˈbrīt-nəs \

Medical Definition of brightness 

: 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

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Comments on brightness

What made you want to look up brightness? Please tell us where you read or heard it (including the quote, if possible).


exaggeratedly or childishly emotional

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