Definitions:

1. Describes something that emits a soft, glowing light without heat, and continues to glow even after the source of energy is removed. ADJECTIVE
   • The stars on the ceiling were coated with phosphorescent paint and glowed all night.
2. Refers to the property or phenomena of emitting light, in the abscence of heat or without being heated, for a prolongued period of time after exposure to and absorption of radiant energy or light. ADJECTIVE
   • The watch hands were phosphorescent, making it easy to read the time in the dimness.

Synonyms:

• glow-in-the-dark
• luminescent
• radiant