British thermal unit

Noun.  he quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit at a particular temperature (there are several different precise definitions) and a pressure of one atmosphere.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.