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giga-

A decimal multiplier prefix in SI, signifying 10⁹, or one billion, of the unit to which it is prefixed. From a Greek root meaning “giant.” Symbol, G.

The giga-’s progress toward official acceptance began in 1940 with a draft proposal made by Technical Committee ISA-9 d 2 of the International Federation of National Standardizing Associations, the predecessor of the ISO. Its legalization was delayed by World War II. In 1948 the General Assembly of the International Union for Pure and Applied Physics approved it, on the recommendation of its Commission on Symbols, Units and Nomenclature. The prefix was widely used, but not actually approved until the adoption of SI by the Eleventh CGPM in 1960.