What does "board of trade unit" mean?

a unit of energy equal to the work done by a power of 1000 watts operating for one hour

What is a synonym for "board of trade unit"?

Common synonyms include: b.t.u., kilowatt hour, kw-hr.

Rare ·Advanced level

Noun

1
a unit of energy equal to the work done by a power of 1000 watts operating for one hour wordnet