#nanosecond  one billionth of a second; one thousandth of a microsecond
  supertype:  #time_unit__unit_of_time  a unit for measuring time periods
  part of:  #microsecond
  part:  #picosecond  one trillionth of a second; one thousandth of a nanosecond
     part:  #femtosecond  one quadrillionth of a second; one thousandth of a nanosecond
        part:  #attosecond  one quintillionth of a second; one thousandth of a femtosecond

No statement uses or specializes #nanosecond; click here to add one.