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.n. 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.n. 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.n. In geometry, a ray conceived as revolving about its starting-point.n. A substance that emits rays, specifically N-rays.