The Collaborative International Dictionary
Radiant \Ra"di*ant\ (r[=a]"d[i^]*ant), a. [L. radians, -antis, p. pr. of radiare to emit rays or beams, fr. radius ray: cf. F. radiant. See Radius, Ray a divergent line.]
Emitting or proceeding as from a center; resembling rays; radiating; radiate.
-
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. Beaming with vivacity and happiness; as, a radiant face.
(Her.) Giving off rays; -- said of a bearing; as, the sun radiant; a crown radiant.
(Bot.) Having a raylike appearance, as the large marginal flowers of certain umbelliferous plants; -- said also of the cluster which has such marginal flowers.
-
(Physics) Emitted or transmitted by radiation; as, a radiant energy; radiant heat.
Radiant energy (Physics), energy given out or transmitted by radiation, as in the case of light and radiant heat.
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.
Radiant point. (Astron.) See Radiant, n., 3.
Wiktionary
n. Energy in a form that can radiate, generally electromagnetic energy.
WordNet
n. energy that is transmitted in the form of (electromagnetic) radiation; energy that exists in the absence of matter
Wikipedia
In radiometry, radiant energy is the energy of electromagnetic and gravitational radiation. The SI unit of radiant energy is the joule (J). The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time. The symbol Q is often used throughout literature to denote radiant energy ("e" for "energetic", to avoid confusion with photometric quantities). In branches of physics other than radiometry, electromagnetic energy is referred to using E or W. The term is used particularly when electromagnetic radiation is emitted by a source into the surrounding environment. This radiation may be visible or invisible to the human eye.
Usage examples of "radiant energy".
And so he was only being consistent when, in his lectures before the Royal Institution in London, and the British Association in Sheffield in 1879, after showing to an amazed scientific audience the newly discovered properties of electricity, he came to the climax of his exposition by saying: 'We have seen that in some of its properties Radiant Matter is as material as this table, whilst in other properties it almost assumes the character of Radiant Energy.
The ship was being spun through necessity to permit some of the impinging radiant energy to re-radiate on the “.
It was solved drastically by planning to place the pile proper outside the satellite, unshielded, and let it waste its radiant energy.
Then it will soak up any radiant energy that hits it, and give it up again as electrical power.
The wall was tight, the only avenue of escape of all that fiercely radiant energy was straight upward.