luminosity

noun

lu·​mi·​nos·​i·​ty ˌlü-mə-ˈnä-sə-tē 

plural luminosities

1

a

: the quality or state of being luminous

b

: something luminous

2

a

: 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)

Synonyms

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

Examples of luminosity in a Sentence

the luminosity of the fireflies made for an enchanting nighttime show

Recent Examples on the Web

These can frame specific areas of the room, or simply create a welcoming luminosity, and are often affordable and easy to change. —Hannah Coates, Vogue, 25 Sep. 2024

Unlike most other picture settings, raising or lowering luminosity doesn’t affect picture quality or accuracy. —Ryan Waniata, WIRED, 12 Sep. 2024

Photograph: Courtesy of the Caltech Archives and Special Collections Measurements of H0 improved as astronomers got better at calibrating the relationship between Cepheids’ pulsation frequency and their luminosity. —Liz Kruesi, WIRED, 8 Sep. 2024

They're infused with finely ground reflective pearls, which catch the light for luminosity without veering into shiny territory. —Deanna Pai and Sarah Han, Allure, 3 Sep. 2024

Word History

Etymology

borrowed from Middle French & Medieval Latin; Middle French luminosité, borrowed from Medieval Latin lūminōsitāt-, lūminōsitās, from Latin lūminōsus "full of light, luminous" + -itāt-, -itās -ity

First Known Use

1634, in the meaning defined at sense 1a

Kids Definition

luminosity

noun

lu·​mi·​nos·​i·​ty ˌlü-mə-ˈnäs-ət-ē 

plural luminosities

1

: the quality or state of being luminous : brightness

2

: something luminous

Medical Definition

luminosity

noun

lu·​mi·​nos·​i·​ty ˌlü-mə-ˈnäs-ət-ē 

plural luminosities

1

: the quality or state of being luminous

2

a

: the relative quantity of light

b

: the comparative degree to which light of a given wavelength induces the sensation of brightness when perceived