2. (Geom.) A straight line proceeding from a given point, or
fixed pole, about which it is conceived to revolve.
3. (Astron.) The point in the heavens at which the apparent
paths of shooting stars meet, when traced backward, or
whence they appear to radiate.
2. Especially, emitting or darting rays of light or heat;
issuing in beams or rays; beaming with brightness;
emitting a vivid light or splendor; as, the radiant sun.
Mark what radiant state she spreads. --Milton.
3. Beaming with vivacity and happiness; as, a radiant face.
4. (Her.) Giving off rays; -- said of a bearing; as, the sun
radiant; a crown radiant.
5. (Bot.) Having a raylike appearance, as the large marginal
flowers of certain umbelliferous plants; -- said also of
the cluster which has such marginal flowers.
{Radiant energy} (Physics), energy given out or transmitted
by radiation, as in the case of light and radiant heat.
{Radiant 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.
{Radiant point}. (Astron.) See {Radiant}, n., 3.