#British_thermal_unit__BTU__Btu__btu__b.th.u.  a unit of heat equal to the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure; equivalent to 251.997 calories
  supertype:  work_unit__heat_unit__energy_unit  a unit of measurement for work
  part of:  therm  a unit of heat equal to 100,000 British thermal units

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