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nano-

A decimal submultiplier prefix in SI, signifying 10⁻⁹, or one billionth (in the American meaning of billion), of the unit to which it is prefixed. From a Greek root meaning “dwarf.” Symbol, n.

The nano-'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. The nano-'s legalization was delayed by the war, but 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 11th CGPM in 1960.

In Chinese, the nano- is haowei.