#femtometer__femtometre__fermi  a metric unit of length equal to one quadrillionth of a meter
  supertype:  #metric_linear_unit  a linear unit of distance in metric terms
  part of:  #picometer__picometre__micromicron  a metric unit of length equal to one trillionth of a meter
     part of:  #angstrom_unit__angstrom__A  a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
        part of:  #nanometer__nanometre__millimicron__micromillimetre  a metric unit of length equal to one billionth of a meter
           part of:  #micron__micrometer  a metric unit of length equal to one millionth of a meter
              part of:  #millimeter__millimetre__mm  a metric unit of length equal to one thousandth of a meter
                 part of:  #centimeter__centimetre__cm  a metric unit of length equal to one hundredth of a meter
                    part of:  #decimeter__decimetre__dm  a metric unit of length equal to one tenth of a meter
                       part of:  #meter__metre__m  the basic unit of length adopted under the System International d'Unites (approximately 1.094 yards)
                          part of:  #decameter__dekameter__decametre__dekametre__dam__dkm  a metric unit of length equal to ten meters
                             part of:  #hectometer__hectometre__hm  a metric unit of length equal to 100 meters
                                part of:  #kilometer__kilometre__km__klick  a metric unit of length equal to 1000 meters (or 0.621371 miles)
                                   part of:  #myriameter__myriametre__mym  a metric unit of length equal to 10,000 meters

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