a capacitor used in a decoupling network, a capacitor for providing an alternating-current path of comparatively low impedance at the frequencies of disturbing currents down to the chassis ground, decoupling - reduction of a common impedance between parts of a circuit, eg by using a by-pass capacitor, capacitor - an electronic component that holds a charge. It comes in varying sizes for use in power supplies. It is also constructed as microscopic cells in dynamic RAM chips.