phosphorescencemedical dictionary

1. <chemistry> Emission of light following absorption of radiation. Emitted light is of longer wavelength than the exciting radiation and is a result of decay of electrons from the triplet to the ground state. Lasts longer than fluorescence electron decay from singlet to ground state) and occurs after a longer delay.

2. <biology> Popularly misused as a term for biological luminescence, for example by fireflies.

(31 Dec 1997)