adjective
Radiating light and/or heat.
Emitted as radiation.
(figurative) Beaming with vivacity and happiness.
(figurative) Strikingly beautiful.
Emitting or proceeding as if from a center.
(heraldry, of a bearing) Giving off rays.
(botany) Having a ray-like appearance, like the large marginal flowers of certain umbelliferous plants; said also of the cluster which has such marginal flowers.
noun
A point source from which radiation is emitted.
(astronomy) The apparent origin, in the night sky, of a meteor shower.
(geometry) A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve.