1.  luminescence(n = noun.phenomenon) - light not due to incandescence; occurs at low temperatures;
is a kind of light, visible light, visible radiation
has particulars: bioluminescence, chemiluminescence
Derived forms verb luminesce₁, adjective luminescent₁

2.  luminescence(n = noun.attribute) glow - light from nonthermal sources;
is a kind of brightness, brightness level, light, luminance, luminosity, luminousness
Derived forms verb luminesce₁, adjective luminescent₁

1.  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.  The faculty or power of producing light by biological processes, as in the firefly and glowworm. Also called bioluminescence. [Webster 1913 Suppl.]

luminescence, n. the emission of light by a substance other than as a result of incandescence.

Derivative:
luminescent adj.

Etymology:
as LUMEN + -ESCENCE (see -ESCENT)