luminescence

n. [ See Luminescent. ] 1. (Physics) Any emission of light not ascribable directly to incandescence, and therefore occurring at low temperatures, as in phosphorescence and fluorescence or other luminous radiation resulting from vital processes, chemical action, friction, solution, or the influence of light or of ultraviolet or cathode rays, etc. [ Webster 1913 Suppl. ]

2. (Zool.) (a) The faculty or power of producing light by biological processes, as in the firefly and glowworm. Also called bioluminescence. (b) The light produced by biological or biochemical processes. Also called bioluminescence. [ Webster 1913 Suppl. +PJC ]