'Therm' definitions:

Definition of 'therm'

(from WordNet)
noun
A unit of heat equal to 100,000 British thermal units

Definition of 'Therm'

From: GCIDE
  • Therm \Therm\ (th[~e]rm), n. one of several units of heat, especially one equivalent to
  • 1000 large calories, or 100,000 British thermal units. [PJC]