The rate of flow of radiant energy (electromagnetic waves) WordNet 3.0 & Open English WordNet

In radiometry, radiant flux or radiant power is the radiant energy emitted, reflected, transmitted, or received per unit time, and spectral flux or spectral power is the radiant flux per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. Wikipedia

physical quantity Wikidata