definition of dielectric
A dielectric is a substance in which an electric field gives rise to no net flow of electric charge but only to a displacement of charge. The type of dielectric used between the plates of a capacitor will alter the capacitance of the capacitor. A dielectric is a non-conductor of electricity, or an insulator. 1  A dielectric is a substance in which an electric field gives rise to no net flow of electric charge but only to a displacement of charge. 2  The type of dielectric used between the plates of a capacitor will alter the capacitance of the capacitor.