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

The consensus was to focus first on upgrading the LHC to increase its luminosity—the number of collisions per second—rather than immediately beginning to build a successor. — Florencia Canelli, Scientific American, 1 July 2026

Tory Burch Sublime Shimmer Ideal for weddings, summer parties and evening dinners, adding subtle luminosity without overpowering your look. — Corein Carter, Forbes.com, 29 June 2026

Terzan 5 is a globular cluster — a huge sphere of stars with a total mass two million times greater than our sun's and a total luminosity 800,000 times greater. — Keith Cooper, Space.com, 22 June 2026

From glossy tints to sheer, milky polishes, one of the biggest trends of summer is simply enhancing your natural nails’ luminosity. — Ariel Wodarcyk, InStyle, 20 June 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