A metric unit of distance equal to 10-9 meter. Introduced in 1951, the nanometer replaced the millimicron. One nanometer equals 0.001 micrometer or 10 angstroms
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}