A nanometre (American spelling: nanometer; symbol nm) (Greek: νάνος, nanos, "dwarf"; μέτρον, metrοn, "unit of measurement") is a unit of length in the metric system, equal to one billionth of a meter. It is one of the more often used units for very small lengths, and equals ten Ångström, an internationally recognized non-SI unit of length. It is often associated with the field of nanotechnology and the wavelength of light. Fo… (More on Nanometre)