from
The Collaborative International Dictionary of English v.0.48
Ohm \Ohm\ ([=o]m), n. [So called from the German electrician, G.
S. Ohm.] (Elec.)
The standard unit in the measure of electrical resistance,
being the resistance of a circuit in which a potential
difference of one volt produces a current of one amp['e]re.
As defined by the International Electrical Congress in 1893,
and by United States Statute, it is a resistance
substantially equal to 10^{9} units of resistance of the C.
G. S. system of electro-magnetic units, and is represented by
the resistance offered to an unvarying electric current by a
column of mercury at the temperature of melting ice 14.4521
grams in mass, of a constant cross-sectional area, and of the
length of 106.3 centimeters. As thus defined it is called the
{international ohm}.
[1913 Webster]
{Ohm's law} (Elec.), the statement of the fact that the
strength or intensity of an electrical current is directly
proportional to the electro-motive force, and inversely
proportional to the resistance of the circuit.
[1913 Webster]