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 of luminosity

• brightness
• brilliancy
• brilliance
• lightness

Examples of luminosity in a Sentence

the luminosity of the fireflies made for an enchanting nighttime show

Recent Examples on the Web

Duchesse, twill and double satin will add luminosity and fluid movement to the structure of the pieces. —Luisa Zargani, Footwear News, 25 Feb. 2026

Revell’s paintings reflect her appreciation for nature, light and color and her ability to capture atmosphere and luminosity. —Nollyanne Delacruz, Mercury News, 24 Feb. 2026

That giant jump in luminosity will give researchers unprecedented access to rare interactions, subtle effects, and deeper insights into the Higgs boson. —Georgina Jedikovska, Interesting Engineering, 24 Feb. 2026

Almost No Stars Preliminary analysis suggests CDG-2 has the luminosity of about 6 million Sun-like stars. —Ryan Brennan, Charlotte Observer, 23 Feb. 2026

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

Rhymes for luminosity

• adiposity

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