General English


  • The point in the sky from which meteors of a particular shower appear to come. The meteoroids which produce the meteors in the upper atmosphere are in the same orbit around the Sun, and enter the Earth’s atmosphere parallel to each other, so that they appear to come from a single radiant by the perspective effect. The constellation in which the radiant is found gives its name to the shower, unless there is room for ambiguity in which case some more specific name (like the April and June Lyrids) is adopted.


  • Emitting radiation, such as light or heat.
  • A point, particle, body, object, or region from which radiation, such as light or heat, is emitted.
  • Emitted in all directions from a given location or object, such as a point source or body.
  • Consisting of, or pertaining to, radiation, such as light or heat.


  • adjective lit with a bright or glowing light
  • adjective sending out light, heat or other energy in the form of rays or waves