electromagnetic radiation

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Energy having both the form of electromagnetic waves and the form of a stream of photons and traveling at the speed of light in a vacuum. The entire range of frequencies and wavelengths of electromagnetic radiation makes up the electromagnetic spectrum.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Radiation (quantized as photons) consisting of oscillating electric and magnetic fields oriented perpendicularly to each other, moving through space.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge