A unit of energy equal to 10 therms, 1 million Btu, or about 1.055 057 gigajoules (GJ). This unit is used in the energy industry as a synonym for the million-Btu (MM Btu)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}