1. 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; [syn: British thermal unit, BTU, B.Th.U.]
WordNet (r) 3.0 (2006):
B.Th.U.
n 1: 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 [syn:
British thermal unit, BTU, B.Th.U.]