electromagnetic wave

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

• noun A wave of electromagnetic energy that is radiated by an accelerating or oscillating electric charge and propagates through a vacuum or a material medium as a periodic disturbance of the electromagnetic field at a frequency within the electromagnetic spectrum.

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

• noun physics electromagnetic radiation, such as light and radio waves

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