The American Heritage® Dictionary of the English Language, 4th Edition
n. Modulation of the frequencies of electromagnetic waves occurring when the waves interact as they are transmitted through a nonlinear electronic system.
n. modulation of the different frequencies of interacting waves
Word Usage
"Sennheiser's new low intermodulation mode provides roughly 30 percent more simultaneous channels in a given frequency band and works by increasing the linearity of the amplifier's"