phosphorescence

This term describes a specific type of luminescence where light is emitted slowly over time after the energy source is removed. It evokes a ghostly, ethereal, or supernatural quality, often associated with deep-sea creatures or glowing minerals in a dark cave. As an uncountable noun, it refers to the phenomenon or the quality of the light itself. It does not have a plural form in standard usage, as it describes a physical property rather than a discrete object.