a unit of electrical resistance equal to the resistance between two points on a conductor when a potential difference of one volt between them produces a current of one ampere

source: WordNet 3.0

German physicist who formulated Ohm's law (1787-1854)

source: WordNet 3.0

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 ampére. 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.