radiant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Emitting heat or light.
• adjective Consisting of or emitted as radiation.
• adjective Filled with light shining especially as rays; brightly shining: synonym: bright.
• adjective Showing or expressing vitality or joy.
• adjective Splendid; glorious.
• noun An object or point from which light or heat rays are emitted.
• noun Astronomy The apparent celestial origin of a meteoric shower.

from The Century Dictionary.

• noun In geometry, a ray conceived as revolving about its starting-point.
• noun A substance that emits rays, specifically N-rays.
• Darting, shooting, or emitting rays of light or heat; shining; sparkling: beaming with brightness, literally or figuratively: as, the radiant sun; a radiant countenance.
• Giving out rays; proceeding in the form of rays; resembling rays; radiating; also, radiated; radiate: as, radiant heat.
• In heraldry:
• Edged with rays: said of an ordinary or other bearing such as is usually bounded with straight lines, the rays generally appearing like long indentations. See ray, 8.
• Giving off rays, which do not form a broken or indented edge to the bearing, but stream from it, its outline being usually perfect and the rays apparently streaming from behind it.
• In botany, radiating; radiate.
• Synonyms Beaming, resplendent. See radiance.
• noun In optics, a luminous point or object from which light radiates to the eye, or to a mirror or lens; a point considered as the focus of a pencil of rays.
• noun In astronomy, the point in the heavens from which the shooting-stars of a meteoric shower seem to proceed: thus, the radiant of the shower of November 13th is near the star ζ Leonis, and these meteors are hence called the Leonides.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Opt.) The luminous point or object from which light emanates; also, a body radiating light brightly.
• noun (Geom.) A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve.
• noun (Astron.) The point in the heavens at which the apparent paths of shooting stars meet, when traced backward, or whence they appear to radiate.
• adjective Emitting or proceeding as from a center; resembling rays; radiating; radiate.
• adjective Especially, emitting or darting rays of light or heat; issuing in beams or rays; beaming with brightness; emitting a vivid light or splendor.
• adjective Beaming with vivacity and happiness.
• adjective (Her.) Giving off rays; -- said of a bearing
• adjective (Bot.) Having a raylike appearance, as the large marginal flowers of certain umbelliferous plants; -- said also of the cluster which has such marginal flowers.
• adjective (Physics) Emitted or transmitted by radiation.
• adjective (Physics) energy given out or transmitted by radiation, as in the case of light and radiant heat.
• adjective heat proceeding in right lines, or directly from the heated body, after the manner of light, in distinction from heat conducted or carried by intervening media.
• adjective (Astron.) See Radiant, n., 3.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Radiating light and/or heat.
• adjective Emitted as radiation.
• adjective Bright, glowing or filled with light.
• noun A point source from which radiation is emitted.
• noun astronomy The apparent origin, in the night sky, of a meteor shower.
• noun A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective radiating or as if radiating light