Dictionary.net

Interference caused by two signals becomingpartially superimposed on each other due to electromagnetic(inductive) or electrostatic (capacitive) coupling between theconductors carrying the signals. A common example ofcrosstalk is where the magnetic field from changing currentflow in one wire induces current in another wire runningparallel to the other, as in a transformer. Crosstalk can bereduced by using shielded cables and increasing the distancebetween conductors.