The inverse of impedance. Usually denoted as "Y" in electrical equations, or 1/Z, Z being impedance. The
unit value of admittance is commonly dubbed "mhos" (backwards
spelling of ohms.) It is a measure of the lack of impedance in a circuit, system of circuits or a specific conductor. A short circuit should, ideally, have an admittance of
infinity. An open circuit will have an ideal admittance of 0 mhos.