Definition of "luminosity" []

• 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. Also called luminosity factor. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "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."
• "The rods detect motion — changes in luminosity — better than do the cones."
• "Polaris fluctuates in its short-term luminosity as well."