WordNet (r) 3.0 (2006):

nanometre
    n 1: a metric unit of length equal to one billionth of a meter
         [syn: nanometer, nanometre, nm, millimicron,
         micromillimeter, micromillimetre]

The Free On-line Dictionary of Computing (30 December 2018):

nanometre

    10^-9 metres; one thousand millionth part of a metre.

   The wavelength of visible light and dimensions in
   nanotechnology are typically measured in nanometres.

   (2003-05-02)