BRITISH THERMAL UNIT(noun)Did you mean?RhymesDefinitions There is 1 meaning of the phrase British Thermal Unit. British Thermal Unit - as a noun 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 Synonyms (Exact Relations)b.th.u.btuWord Variations & RelationsStarts BStarts BRStarts BRIStarts BRITEnds TEnds ITEnds NITEnds UNITStarts B & ends TStarts BR & ends TStarts B & ends ITA-Z Proximitiesbritches15brith10briths11briticismbritish British Thermal Unit britisherbritishismbritonbrits7britschka20