释义 
		[ brahyt -nis ] SHOW IPA 
/ ˈbraɪt nɪs / PHONETIC RESPELLING 
SEE SYNONYMS FOR brightness  ON THESAURUS.COM
noun the quality of being bright.  
Optics . the luminance of a body, apart from its hue or saturation, that an observer uses to determine the comparative luminance of another body. Pure white has the maximum brightness, and pure black the minimum brightness. 
Origin of brightness  before 950; Middle English brihtnes, Old English beorhtnes. See bright, -ness
Words nearby brightness  bright-field, bright idea, bright lights, brightline, brightline spectrum, brightness , Brighton, Brighton and Hove, brights, Bright's disease, bright side
Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Example sentences from the Web for brightness According to Donahue, an ideal goal would be to reduce the brightness  of these satellites by a factor of 100.
Satellite mega-constellations risk ruining astronomy forever | Neel Patel| September 2, 2020| MIT Technology Review
SpaceX tested out a prototype “DarkSat” paint on a Starlink satellite in January, but it failed to significantly reduce brightness .
Satellite mega-constellations risk ruining astronomy forever | Neel Patel| September 2, 2020| MIT Technology Review
A remote control helps you adjust the brightness  and set a timer for turning the lights on and off.
Twinkle lights that instantly cheer up your home | PopSci Commerce Team| August 27, 2020| Popular Science
Astronomers seek out potential exoplanets by looking for fluctuations in the brightness  of distant stars.
50 new planets, including one as big as Neptune, are identified using A.I. | rhhackettfortune| August 26, 2020| Fortune
The fields are weak and the brightness  of the sun outshines its corona.
Check out the first-ever map of the solar corona’s magnetic field | Lisa Grossman| August 21, 2020| Science News
Hop in bed with your iPad or iPhone and turn the brightness  all the way up.
Body Hack: How to See in the Dark (Like Pirates!) | Brian Ries| December 10, 2013| DAILY BEAST
Consumer Reports last month actually ran one for 25,000 hours straight and it still maintained its brightness .
Why You Should Give LED Light Bulbs for Christmas. Seriously. | Daniel Gross| December 4, 2013| DAILY BEAST
Specifically, the law said a bulb should provide 100 watts of brightness  while using 72 watts or less.
The Best Green Idea in Obama’s Climate-Change Speech | Daniel Gross| June 25, 2013| DAILY BEAST
The champagne brings out the brightness  and tang of the grapefruit.
What to Eat | Cookstr.com| August 11, 2009| DAILY BEAST
It was poignant because with her brightness  and her zest for life, she is also dealing with something very dark.
The Queen of Queens | Rachel Syme| March 16, 2009| DAILY BEAST
Some women's faces are in their brightness  a prophecy, and some in their sadness a history.
Oriental Women | Edward Bagby Pollard
This is that contemplation of inexhaustible melancholy, whose shadow eclipses the brightness  of the world.
A Defence of Poetry and Other Essays | Percy Bysshe Shelley
How many a heart, sinking under its bitter burden of care, is reawakened to hope by that first spring day of brightness !
Verner's Pride | Mrs. Henry Wood
Then Diana stepped out of the brightness  of the drawing-room.
The Rhodesian | Gertrude Page
It had the brightness  of colouring and easy fascination of a child's.
Diana Tempest, Volume II (of 3) | Mary Cholmondeley
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British Dictionary definitions for  brightness noun the condition of being bright 
physics  a former name for luminosity (def. 4)
psychol  the experienced intensity of light 
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Words related to brightness illumination, brilliance, luster, shine, light, gloss, glaze, luminosity, acumen, smarts, competence, aptitude