Pronunciation: (floo-res'uns, flô-, flō-), [key]
—n. Physics, Chem.
1. the emission of radiation, esp. of visible light, by a substance during exposure to external radiation, as light or x-rays. Cf. phosphorescence (def. 1).
2. the property possessed by a substance capable of such emission.
3. the radiation so produced.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.