from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The condition or quality of being luminous.
  • noun Something luminous.
  • noun The ratio of luminous flux at a specific wavelength to the radiant flux at the same wavelength.

from The Century Dictionary.

  • noun The quality of being luminous or bright; luminousness; the radiation or reflection of light.
  • noun Specifically, the intensity of light in a color, measured photometrically.
  • noun In botany, phosphorescence.

from the GNU version of the Collaborative International Dictionary of English.

  • noun The quality or state of being luminous; luminousness.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun uncountable the state of being luminous, or a luminous object; brilliance or radiance
  • noun physics the ratio of luminous flux to radiant flux at the same wavelength; the luminosity factor
  • noun astronomy the rate at which a star radiates energy in all directions

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the quality of being luminous; emitting or reflecting light


Sorry, no etymologies found.


  • The word luminosity describes the nature of celestial light, and the music of composer James Whitbourn is a celebration of that light: peaceful, radiant and clear.

    James Whitbourn's Celestial Sounds

  • The rods detect motion — changes in luminosity — better than do the cones.

    Double Words Optical Illusion – Ambigram

  • Polaris fluctuates in its short-term luminosity as well.

    The Independent - Frontpage RSS Feed

  • Polaris fluctuates in its short-term luminosity as well.

    The Independent - Frontpage RSS Feed

  • 25In their reply, Pettersson and Kirsch stressed the fact that the ratio in luminosity between alpha and H-particles (protons) does not permit such a mistake as Bates and Rogers attributed to them. 38 On July 19, even before the articles were published, Rutherford sent his results to Pettersson. 39 In a friendly and grateful response on July 27, Pettersson tried to reconcile and explain the discrepancies.

    Trafficking Materials and Gendered Experimental Practices: Radium Research in Early 20th Century Vienna

  • rates rate of change in star rotation rate star magnetic field variability stellar wind strength and variability short period variation in parent star diameter star's carbon to oxygen ratio star's space velocity relative to Local Standard of Rest star's short term luminosity variability star's long term luminosity variability amplitude and duration of star spot cycle number

    Reasons To Believe -

  • How could the observer call the luminosity thus produced?

    Experiments with Alternate Currents of High Potential and High Frequency

  • The orchestration here is very thick, but not at all heavy or cluttered; in fact, it has a uniquely peculiar luminosity, which is animated by its actually relatively thin, more truly contrapuntal texture.


  • Buddhism is less tongue-tied than this: reality has all the qualities of a Buddha, wakefulness, intelligence, compassion — attributes which are often called "luminosity" to distinguish it from sheer lack of existence.

    Hegel on Buddhism

  • The third turning teachings are often called "luminosity" to distinguish them from the second turning teachings on emptiness, though they are said not to contradict this view, but to complement it.

    Hegel on Buddhism


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  • "And yet one did not find in Bergotte's speech a certain luminosity which in his books, as in those of some other writers, often modified in the written sentence the appearance of its words."

    -- Within a Budding Grove by Marcel Proust, translated by C.K. Scott Moncrieff and Terence Kilmartin, Revised by D.J. Enright, p 173 of the Modern Library paperback edition

    April 20, 2008

  • "But I hesitated for an instant, for the sky-blue border of her dress added to her face a beauty, a luminosity, without which she would have seemed to me harder."

    birds, symbols of death and resurrection."

    --The Captive & The Fugitive by Marcel Proust, translated by C.K. Scott Moncrieff and Terence Kilmartin, revised by D.J. Enright, p 538 of the Modern Library paperback edition

    February 11, 2010