noun
: the radiant energy that is emitted by a source per unit time per unit solid angle in a given direction under conditions that the source may be considered as sensibly a point source and that is measured in units of watts per steradian
noun
: the radiant energy that is emitted by a source per unit time per unit solid angle in a given direction under conditions that the source may be considered as sensibly a point source and that is measured in units of watts per steradian
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012