When some object gives off light, that light is called luminescence. The luminescence of a lighthouse helps keep boats safe on foggy nights.

Glow-in-the-dark stars stuck to your bedroom ceiling have a luminescence you can see when you turn out the light at night, and lightning bugs blink on and off with luminescence in the summertime. Luminescence, scientifically speaking, describes a glow or light that's emitted at a cool temperature, rather than one caused by a fire, for example. The Latin root is lumen, or "light."

Definitions of luminescence

n light not due to incandescence; occurs at low temperatures

luminescence produced by physiological processes (as in the firefly)
luminescence resulting from a chemical reaction as the oxidation of luciferin in fireflies
Type of:
light, visible light, visible radiation
(physics) electromagnetic radiation that can produce a visual sensation

n light from nonthermal sources

Type of:
brightness, brightness level, light, luminance, luminosity, luminousness
the quality of being luminous; emitting or reflecting light

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, can put you on the path to systematic vocabulary improvement.