lu·​mi·​nos·​i·​ty | \ ˌlü-mə-ˈnä-sə-tē How to pronounce luminosity (audio) \
plural luminosities

Definition of luminosity

1a : the quality or state of being luminous
b : something luminous
2a : the relative quantity of light
b : relative brightness of something
3 : the relative quantity of radiation emitted by a celestial source (such as a star)

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Examples of luminosity in a Sentence

the luminosity of the fireflies made for an enchanting nighttime show
Recent Examples on the Web Betelgeuse, a star in the Orion constellation—the right shoulder, to be exact— has dramatically decreased its luminosity, and scientists believe this shift could usher in a new era for the star. Jennifer Leman, Popular Mechanics, "As Betelgeuse Dims, Scientists Wonder If We're Watching a Star Die," 30 Dec. 2019 Floating above their music was a voice with the kind of luminosity one longs for in Bach, that of the marvelous young soprano Elijah McCormack. Joe Banno, Washington Post, "One aria sums up a joyful Washington Bach Consort ‘Christmas Oratorio’," 23 Dec. 2019 But the result was nothing but positive: During Dermaologica's clinical studies on this product, there were visible signs of luminosity after one application. Maya Allen, Marie Claire, "Why Dermalogica's Phyto-Nature Firming Serum Is Worth It," 25 Sep. 2019 Pulsations from one x-ray binary imply that the compact companion is a neutron star that must be accreting huge amounts of material from its companion to generate its unusually high luminosity. Belinda J. Wilkes, Scientific American, "The Universe through X-ray Eyes," 26 Nov. 2019 The effect is something like stained glass, the once-dense loaves now delicate and ultra-lightweight, glowing with a gentle, golden luminosity. Helen Rosner, The New Yorker, "Holiday Gift Guide for Foodies: From Murderous Mermaid Salt to Lamps Made Out of Croissants," 12 Dec. 2019 From the start of the overture, the score bathed the ear in textured sound that conveyed, in its gently shifting luminosity, something of the distance of the archaic. Washington Post, "A new leader and new sounds at the Met: Philip Glass’s striking ‘Akhnaten’," 17 Nov. 2019 This comes to the surface as luminosity and as stellar wind, which can blow off the surface at an astonishing 1,700 kilometers per second, or approximately 3,802,792 miles per hour. David Grossman, Popular Mechanics, "Astronomers Finally Able to See Beneath Surface of Mysterious Blue Supergiants," 7 May 2019 According to the brand's website, it can be used on their own or mixed in with your moisturizer to enhance its luminosity. Kaleigh Fasanella, Allure, "M.A.C.’s Supreme Beam Summer 2018 Collection Features Its Discontinued Hyper Real Foundation," 6 Aug. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'luminosity.' 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 luminosity

1634, in the meaning defined at sense 1a

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Time Traveler for luminosity

Time Traveler

The first known use of luminosity was in 1634

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Statistics for luminosity

Last Updated

16 Jan 2020

Cite this Entry

“Luminosity.” The Dictionary, Merriam-Webster Inc., Accessed 28 January 2020.

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More Definitions for luminosity


lu·​mi·​nos·​i·​ty | \ ˌlü-mə-ˈnäs-ət-ē How to pronounce luminosity (audio) \
plural luminosities

Medical Definition of luminosity

1 : the quality or state of being luminous
2a : the relative quantity of light
b : the comparative degree to which light of a given wavelength induces the sensation of brightness when perceived

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Comments on luminosity

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


showing steady, earnest care and effort

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