FLUORESCENCE

n. emission of electromagnetic radiation (especially as visible light); fluorescent light

Fluorescence is a luminescence that is mostly found as an optical phenomenon in cold bodies, in which the molecular absorption of a photon triggers the emission of another photon with a longer wavelength. The energy difference between the absorbed and emitted photons ends up as molecular vibrations or heat. Usually the absorbed photon is in the ultraviolet range, and the emitted light is in the visible range, but this depends on the absorbance curve and Stokes shift of the particular fluorophore. Fluorescence is named after the mineral fluorite, composed of calcium fluoride, which often exhibits this phenomenon.
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Fluorescence /flu·o·res·cence/ the property of emitting light while exposed to light, the wavelength of the emitted light being longer than that of [more]Fluorescence - Community and Resources

Noun
1. light emitted during absorption of radiation of some other (invisible) wavelength
(hypernym) light, visible light, visible radiation
(hyponym) autofluorescence
(derivation) fluoresce

n. fluorescence, emission of electromagnetic radiation (especially as visible light); fluorescent light