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fluorescence

American  
[floo-res-uhns, flaw-, floh-] / flʊˈrɛs əns, flɔ-, floʊ- /

noun

Physics, Chemistry.
  1. the emission of radiation, especially of visible light, by a substance during exposure to external radiation, as light or x-rays.

  2. the property possessed by a substance capable of such emission.

  3. the radiation so produced.


fluorescence British  
/ ˌflʊəˈrɛsəns /

noun

  1. physics

    1. the emission of light or other radiation from atoms or molecules that are bombarded by particles, such as electrons, or by radiation from a separate source. The bombarding radiation produces excited atoms, molecules, or ions and these emit photons as they fall back to the ground state

    2. such an emission of photons that ceases as soon as the bombarding radiation is discontinued

    3. such an emission of photons for which the average lifetime of the excited atoms and molecules is less than about 10 –8 seconds

  2. the radiation emitted as a result of fluorescence Compare phosphorescence

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

fluorescence Cultural  
  1. The emission of light from an object as a result of bombardment by other kinds of electromagnetic radiation, such as x-rays or ultraviolet rays. Fluorescent materials may appear one color when bathed in visible light and another color when exposed to other kinds of electromagnetic radiation.


Discover More

“Black light” depends on fluorescence for its effects.

Other Word Forms


Etymology

Origin of fluorescence

1852; fluor(spar) + -escence, on the model of opalescence ( def. ), in reference to the mineral's newly discovered property


Vocabulary lists containing fluorescence

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Fire salamanders already use their distinctive yellow and black patterns as warning signals, and fluorescence might provide an additional visual cue.

From Science Daily ● Oct. 28, 2026

This additional light influences the measured fluorescence intensity, which scientists use to estimate how densely a particle ionizes the material.

From Science Daily ● Oct. 28, 2026

Understanding whether fluorescence influences communication, mating, or predator avoidance could also contribute to conservation efforts.

From Science Daily ● Oct. 28, 2026

Moerner received the 2014 Nobel Prize in Chemistry for his pioneering contributions to super-resolution fluorescence microscopy.

From Science Daily ● Oct. 17, 2026

Maybe it was my nerves, but his office had the closed-in feeling of a jail cell, metal jalousies at the windows and fluorescence the only light.

From "In the Time of the Butterflies" by Julia Alvarez

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