Etymologically
Log in

luminosity

History Permalink

Etymology and origin of the English word luminosity

Confidence
Established
Formation
Derivation
First attested
1634 Bishop J. Hall, Contemplations More words from the 17th century
Ultimate origin
Latin lūmen
Etymology tree
inherited borrowed derived
Latin lūmen
Aromanian lumi
Italian lume
Romanian lume
English lumen
Latin lūminōsus
Romanian luminos
English luminous
English luminosity
From the same root
Latin lūmināre ← lūmen
Latin lūminō ← lūmen

Pronunciation

  • UK: /ˌluːmɪˈnɒsəti/, /ˌljuːmɪˈnɒsəti/[1]
  • US: /ˌluːməˈnɑːsət̬i/[1]

Etymology

It is formed from English luminous + -ity,[2][3][4] on the model of pairs such as curious and curiosity;[5] the OED and the Shorter Oxford compare the suffix -osity.[2][6] Etymonline allows that it may instead be from French luminosité, a cognate of Medieval Latin lūminōsitās (“splendour”).[7] Luminous is from Latin lūminōsus (“shining, full of light”), from lūmen (“light”),[2][7][8] from a suffixed form of Proto-Indo-European *lewk- (“light, brightness”).[7][8]

Earliest recorded meaning

The quality or condition of being luminous: 1634, in Bishop Joseph Hall's Contemplations on the New Testament.[2][5][7]

Semantic evolution

From the general quality, the word came to mean a luminous thing or point (1853).[2][6] In the late 19th century it became a term of physics: the intensity of light in a colour or flame (1876)[7] and the power of light of a given wavelength to produce the sensation of brightness (1898).[2][6] In astronomy it has meant since 1906 the intrinsic brightness of a star or other body, as distinct from its apparent brightness, which falls with distance, and the rate at which it emits radiation.[2][7][6] In 1964 particle physicists adopted it for a measure of a colliding-beam accelerator, the rate of interactions divided by the cross-section.[2][6]

Timeline

  • 1634 – the quality of being luminous.[2][5]
  • 1853 – something luminous, a luminous point or area.[2]
  • 1876 – the intensity of light in a colour.[7]
  • 1898 – the effectiveness of light of a wavelength in producing brightness.[2]
  • 1906 – in astronomy, the intrinsic brightness of a heavenly body.[2][7]
  • 1964 – in particle physics, a parameter of a colliding-beam accelerator.[2]

Meanings

Noun

  1. The quality or state of being luminous; brightness: the luminosity of her paintings.[9][5][2]
  2. Something luminous; a bright point or area.[9][5][2]
  3. (astronomy) The total radiation given off by a star or other body, its intrinsic brightness, often expressed relative to the Sun's.[9][5][2]
  4. (physics) The brightness of light or a colour as perceived, or the luminous efficiency of light of a given wavelength.[9][5][2]
  5. (particle physics) A measure of a colliding-beam accelerator, the rate of interactions divided by the reaction cross-section.[2][6]

Word family

  • nonluminosity

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  4. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  5. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  6. ^ a b c d e f Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  7. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  8. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
Cite this entry

“Luminosity.” Etymologically, 12 Nov. 2026, etymologically.com/en/luminosity. Accessed 13 Nov. 2026.

Last edited on . ·