General Definition: 1. Any concentrated source of energy (light, heat, sound, etc.) which gives out rays or waves in all directions, like a pattern of lines drawn from the centre of a circle to various point on its edge, or any thing or any action that can be associated with this in a given context. As a Noun: 1. A source of sound energy. English = speaker. 2. A source of light energy. English = light. 3. A source of heat energy. English = radiator, heater. As a Verb or Adjective: 1. Of a source of energy (light, heat, sound, etc.) to give out rays or waves. English = emit, radiate. 2. Of a source of energy (light, heat, sound, etc.) to suddenly start to give out rays or waves. English = turn on. 3. Of a source of light, to give out rays or waves. English = illuminate.