lightening

This term describes a gradual transition toward less density or higher luminosity. It carries a neutral, technical tone often associated with physical adjustments or natural atmospheric changes. It is distinct from lightning, which refers to electrical discharges during a storm.

As a gerund-derived noun, it functions as an uncountable mass noun when referring to the general process of reduction in weight or color. Because it describes an abstract process rather than a discrete object, it does not typically take a plural form and requires partitive constructions if specific instances are being quantified.