Radiant

a. [Lat. radians, p. pr. of radiare, to emit rays or beams, from radius, ray; Fr. radiant, It. & Sp. radiante.]

1. Emitting or proceeding from a center; radiating; 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. “Radiant in glittering arms and beamy pride.” Milton.

Mark what radiant state she spreads. Milton. Radiant heat, 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.