- noun the process or state of spreading out in all directions from a central point
- noun the waves of energy which are given off when heat is transferred
- noun the waves of energy which are given off by a radioactive substance
- The transmission of energy by electromagnetic means rather than by mechanical ones including conduction or convection. Electromagnetic Radiation is the more commonly-used term. In addition, emissions from radioactive decay are usually described as radiation even when they are generally viewed as particles (like alpha or beta particles) rather than waves.
- noun the act or process of sending out rays or waves
- The transmission of energy by means of electromagnetic waves of very long wave length. The energy travels in a straight line at the speed of light and is not affected by the temperature or currents of the air through which it passes.
- The propagation of energy via electromagnetic waves, particle beams, sound, or the like, through a given medium such as space, the atmosphere, or a solid object. Also, the energy so propagated. Also, the process via which this occurs.
- The energy associated with electromagnetic waves. This energy oscillates between its electric and magnetic components. electromagnetic radiation has both wavelike and particle-like properties. Also called electromagnetic radiation.
- A stream of particles, such as electrons, neutrons, protons, or the like. Also, the emission of such particles. Also, the energy propagated via such particles.
- The emission of particles or waves by a radioactive substance. Also, the particles or waves so emitted.
- The exposure to radiation (1), radiation (2), radiation (3), or radiation (4).
- noun waves of energy which are given off by some substances, especially radioactive substances
- noun an emission of energy as rays of heat, light or electromagnetic waves