(geometry) In the International System of Units, the derived unit of plane angular measure of angle equal to the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle. Symbol: rad

plural of radian

The quality of being radiant, shining, bright or splendid. / (physics) The flux of radiation emitted per unit solid angle in a given direction by a unit area of a source.

A point source from which radiation is emitted. / (astronomy) The apparent origin, in the night sky, of a meteor shower.

Radiating light and/or heat. / Emitted as radiation. / Beaming with vivacity and happiness. / Strikingly beautiful. / Emitting or proceeding as if from a center.

Energy in a form that can radiate, generally electromagnetic energy.

plural of radiant energy

plural of radiancy

The property of being radiant; radiance / (physics) The amount of energy emitted, flux.

plural of radiance