-s ə n(t)s noun
( -s )
Etymology: International Scientific Vocabulary lumin- + -escence; originally formed as German lumineszenz
1. : an emission of light that is not ascribable directly to incandescence and therefore occurs at low temperatures, that is produced by physiological processes (as in the firefly), by chemical action, by friction, by electrical action (as the glow of gases in vacuum tubes when subjected to electric oscillations of high frequency or as the glow of certain bodies when subjected to cathode rays), by certain bodies while crystallizing, by suddenly and moderately heating certain bodies previously exposed to light or to cathode rays, or by exposure to light, or that occurs in radioactivity — compare fluorescence , phosphorescence
2. : the light produced by luminescence