ˈōm noun
( -s )
Etymology: after Georg Simon Ohm died 1854 German physicist
1. : the practical mks unit of electric resistance that is equal to the resistance of a circuit in which a potential difference of one volt produces a current of one ampere or to the resistance in which one watt of power is dissipated when one ampere flows through it and that is taken as standard in the United States
2. : a unit of electrical resistance equal to 1.00049 ohms that was formerly taken as the standard in the U.S. — called also international ohm
3. : the cgs unit of acoustic resistance, reactance, and impedance corresponding to a pressure amplitude of one dyne per square centimeter per cubic centimeter per second of flux (volume-velocity) amplitude — called also acoustic ohm